Because we haven't got enough to argue about; here's my idea of a Grenadier Tree.  Keep in mind I haven't sat down and worked out the balancing algorithm so most of the data you see here is approximate.  If anything is unclear, feel free to ask questions.  If I've made some glaring mistake somewhere then I'm open to altering things until it works. 

This tree is designed to make use of as much existing code as possible - all of the animations and FX already exist and only one new mechanic will have to be constructed.

* Handle Explosives
Icon: Blue
Memory Cost: 2
Requires: Disguise (17), Infiltrator.
Upgrades: Debuff Area Radius Bonus (15%), Stun Duration Bonus (10%), Blind Duration Bonus (15%)
Grants: Use of Bomb Defusal Tool

* Sting Grenade
Icon: Red
Memory Cost: 2
Requires: Handle Explosives (19).
IS Cost: 18
Re-use Timer: 10secs
Combat Stance: Spy Style
Range: 16m
When use: Anytime
Affects: Enemies within 4m of selected enemy.
Damage: Thrown DPS (8)
Downgrades: Accuracy (-5pts): 15secs
States: Causes Stun : 1sec
Interlock Accuracy Boost: 15
Cast Timer: 2secs
Concept: Sting Grenades contain a non-lethal blunt force payload capable of incapacitating a target.  Use this ability to interrupt your opponent, creating an opportunity to hit them with a more powerful atack. 
Compare: Overhand Smash, Code Nuke 1.0
Timer D

* Caltrops
Icon: Purple
Memory Cost: 3
Requires: Handle Explosives (20).
IS Cost: 20
Re-use Timer: 24secs
Combat Stance: Spy Style
Range: 16m
When use: Outside Combat
Affects: Enemies within 5m of selected ground point.
Downgrades: Sneak Movement (-60%): 14secs, Invisibility Movement (-60%): 14secs, Movement Speed (-60%): 14secs, Force Combat (-25%): 10secs.
Cast Timer: 2secs
Concept: Caltrops always land point-upwards and are great for hampering opponents.  Use this ability to slow down a group of enemies so you have time to hit them with something big. 
Compare: Neuro-Dart
Timer C

* Disarm Explosive
Icon: Blue
Memory Cost: 2
Requires: Handle Explosives (22), Caltrops.
Removes all Proximity Mines and Claymores within 6m.
Cast Timer: 6secs
Concept: This ability allows a handler of explosives to disable bombs planted by other players.
Compare: Disable Security Devices

* Fragmentation Grenade
Icon: Red
Memory Cost: 3
Requires: Handle Explosives (25).
IS Cost: 22
Re-use Timer: 12secs
Combat Stance: Spy Style
Range: 16m
When use: Anytime
Affects: Enemies within 5m of selected enemy.
Damage: Thrown DPS (15)
Downgrades: Melee Defense (-20pts): 8secs, Ballistic Defense (-20pts): 8secs.
Interlock Accuracy Boost: -30
Cast Timer: 4secs
Concept: The explosion of this grenade pelts enemies with fragments, making them vulnerable to melee and ballistic attacks. 
Compare: Sky-High Sidekick, Code Nuke 2.0, Miasma 1.0/2.0
Timer D

* Flash Bang
Icon: Purple
Memory Cost: 2
Requires: Handle Explosives (27), Fragmentation Grenade.
IS Cost: 22
Re-use Timer: 30secs
Combat Stance: Spy Style
Range: 16m
When use: Outside combat
Affects: Enemies within 6m of selected ground point.
States: Causes enraged: 8secs, Causes blinded: 8secs,
Cast Timer: 3secs
Concept: The device causes a bright flash of light, blinding and enraging those nearby. 
Compare: Flash Bomb, Bullet Spray
Timer A

* Saboteur
Icon: Orange
Memory Cost: 3
Requires: Handle Explosives (30), Caltrops, Fragmentation Grenade.
Grants: Saboteur Upgrade while equipped.
Saboteur Upgrade:
    Thrown Accuracy (10pts)
    Contested Withdraw (6pts)
    Combat Evasion (10%)

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* Minesweeper
Icon: Blue
Memory Cost: 3
Requires: Saboteur, Handle Explosives (33).
Upgrades: Stealth Detection Bonus (10%), Concentration Bonus (10%), Thrown Defense Bonus (5%), Viral Defense Bonus (5%)
Grants: Use of Bomb Placement Tool

* Claymore
Icon: Red
Memory Cost: 4
Requires: Minesweeper (36).
IS Cost: 46
Re-use Timer: 0secs - Placing a new Claymore cancels the previous Claymore. 
Combat Stance: Spy Style
Range: 0m
When use: Outside Combat
Affects: Enemies within 7m of placement.
Damage: Thrown DPS (100) + Causes 80 thrown damage over 30 sec
States: Causes Powerless : 2secs
Downgrades: Sneak Movement (-40%): 30secs, Movement Speed (-40%): 30secs, Invisibility Movement (-40%): 30secs
Cast Timer: 10secs
Concept: Claymores may be placed while Stealthed or visible (No MS).  An enemy must pass within 5m of the placement in order to trigger the explosion. 
Compare: Sever Artery, Suplex
Timer B (Bomb Placement Mechanic)

* Incendiary Grenade
Icon: Red
Memory Cost: 1
Requires: Minesweeper (38).
IS Cost: 30
Re-use Timer: 30secs
Combat Stance: Spy Style
Range: 12m
When use: Outside Combat
Affects: Enemies within 4m of selected enemy.
Damage: Thrown DPS (70)
Cast Timer: 6secs
Concept: This grenade creates a small but intense firey explosion capable of causing serious damage to a group of opponents. 
Compare: Logic Cannon 2.0
Timer B

* Radiation Grenade
Icon: Red
Memory Cost: 1
Requires: Minesweeper (39), Claymore.
IS Cost: 26
Re-use Timer: 14secs
Combat Stance: Spy Style
Range: 16m
When use: Anytime
Affects: Enemies within 5m of selected enemy.
Damage: Thrown DPS (20)
Downgrades: Viral Defense (-30pts): 8secs, Thrown Defense (-30pts): 8secs, Melee Damage (-10pts): 8secs.
Interlock Accuracy Boost: -40
Cast Timer: 4secs
Concept: The explosion of this grenade irradiates the enemy making them vulnerable to thrown or viral attacks. 
Compare: UI Lag 1.0, Logic Bomb 2.0
Timer C

* Proximity Mine
Icon: Red
Memory Cost: 4
Requires: Minesweeper (42).
IS Cost: 50
Re-use Timer: 0secs - Placing a new Proximity Mine cancels the previous Proximity Mine. 
Combat Stance: Spy Style
Range: 0m
When use: Outside Combat
Affects: Enemies within 6m of placement.
Damage: Thrown DPS (200)
Cast Timer: 12secs
Concept: Proximity Mines may be placed while Stealthed or visible (No MS).  An enemy must pass within 4m of the placement in order to trigger the explosion. 
Compare: Punt, Diving Frankensteiner
Timer B (Bomb Placement Mechanic)

* Tear Gas
Icon: Purple
Memory Cost: 1
Requires: Minesweeper (46), Proximity Mine.
IS Cost: 60
Re-use Timer: 60secs
Combat Stance: Spy Style
Range: 8m
When use: Outside combat
Affects: Enemies within 5m of selected ground point.
States: Causes Stun : 4secs, Causes blinded : 20secs
Downgrades: Combat Evasion (-100%): 30secs, Stealth Detection (-100%): 30secs
Cast Timer: 5secs
Concept: This explosive releases a gas which is capable of incapacitating numerous opponents for a short time. 
Compare: Smoke Bomb, Code Flux, Stun Pulse
Timer A

* Demolition Expert
Icon: Orange
Memory Cost: 5
Requires: Minesweeper (50), Claymore, Proximity Mine.
Upgrades: Thrown Area Radius (10%)
Grants: Demolition Expert Upgrade while equipped.
Demolition Expert Upgrade:
    Thrown Accuracy (12pts)
    Contested Withdraw (10pts)
    Combat Evasion (10%)

I foresee mass PVP chaos. I like it though. 

A very impressive and thought out idea, my friend.  My only recommendation would be to make something cool for the tree icons.  Maybe use some of those grenade icons that are tucked away in the game files.

Sounds awesome. Definitely something I would use.

Very nice idea! Nice expansion of a sadly underused game mechanic. From what I've come to understand of the game's structure so far, anything new seems to be within the scope of Rarebit's development abilities (or those of whoever he brought in to do, say, the override abilities, if anyone).

They'd have to take a look at the whole spy branch for balancing etc.. But then thats no bad thing

Vinia wrote:

They'd have to take a look at the whole spy branch for balancing etc.. But then thats no bad thing

I think balancing issues can be handled with hotfixes and stuff. Even if the first attempt is curde, there are enough players willing to use it and share their experience so that certain abilities can be nerfed or upgraded in no time.

I love this Idea. Keep this thread active and develop on the ideas. Maybe some picture examples of trees etc. And who knows maybe it could happen!

Very Nice work!

Ra2za wrote:

Maybe some picture examples of trees etc.

Garu wrote:

My only recommendation would be to make something cool for the tree icons.

I'm not graphically gifted in any way so if people would like to have a go at making icons, they can be my guest.

Sounds Awesome! I had always wished there were more operative style area attacks other than the smoke bomb and a few spray attacks in smgs. plus it looks like all the animations would be just like smoke bomb or planting a bomb with different colored effects. Only thing I don't see already in the game would be calcrops but I'm thinking of actually throwing a lot of little triangular spikes in a small group.

would cause mass havoc, and sounds awesome!

This would be really awesome.