Hmmm, I unfortunately haven't been keeping much track of this, even though its a thread that i'm very interested in. I'll just breeze over a few things
1.) Lets try to keep subject of traits/fast shot out of here, except when in direct relation to grenades. I'll open another topic up for trait discussion soon.
2.) There is a lot of talk of support builds, or using grenades as secondary weapons. Until the system allows for variance in builds and moving away super specialized builds, then i don't think grenades as a secondary weapon is very realistic.
he only way grenades would become support I imagine is if they become closer to rocket launchers. To me they're already in this category. Yes in 1v1 grenades are supreme, but in a firefight with multiple people you're going to be the prime target generally. I've had to use A LOT of grenades to take down people generally (although in all fairness those were frag, i haven't worked with plasma outside of PvE very much.) The biggest advantage grenades have in team fights is simply that I can basically remove one of their combatants from the fight by keeping him on the ground, while my friends target others (hence why i often use frag over plasma, although thats changing with the 5frag change).
Something thats getting on my nerves are people who keep yelling "grenades are OP" or "2 ap per attack is too little!" rather than actually providing some backup. Its nice to see solar provide some number crunching, i wouldn't mind seeing that tested in game though.
Either way here are a handful of ideas for grenades that push them more into the "support" role. If grenade spam is nerfed, and their DPS is severely reduced (or increasing the AP cost to 5-6 as someone said) then i do think grenades need some kind of buff in other areas so that they aren't useless. Mainly i'll suggest additions to grenades, and let the AP/DPS/etc be sorted out by others
* Have grenade splash increased. Unless i'm in PvE with melee monsters that i can easily clump up then grenade splash rarely makes a difference, except when i maybe miss a little. Allow me to actually hit multiple foes who do not work to spread out. My enemies practically have to be adjacent to each other in order for me to hit several, and that almost never happens in PvP
* Allow grenades to cause crippled legs without a need for criticals. Presumably the AP cost would be extremely high if this is implemented
* Simply make grenades like rockets with a shorter range, that is only slightly able to be spammed (If i could shoot 2 rockets, then i should be able to throw 3-4 grenades). Keep the DPS the same as a rocket (including the rocket's reload time) but the advantage being i can keep people on the ground more easily than with rockets (The disadvantage being that I have to get MUCH closer to my target)
Regardless of what happens, i think grenades will remain king in 1v1s unless you nerf them to the point that they're useless in all areas, much like sneak. Sneak provides a HUGE advantage, however these advantages typically exist solely in 1v1. I've seen teams of sneakers very very rarely, but i haven't fought them enough unfortunately to know how that works out (I tend to be by myself in those situations)
As stated though in a team fight grenadiers tend to be target fired pretty quickly. Which is nice, since I can just build my grenadiers as a tank and absorb as much fire as i can so that my sniper glass cannons aren't being taken out. My main role is simply to disable the highest priority, and take on damage so that others don't have to (people tend to shoot the closest target anyways, so getting close with a grenadier works out doubly)