Here are thoughts of some of the things posted:
1.The lucifer cannon's primary shot decays over time, losing damage as it travels. The idea behind this is to prevent people from spamming shots down long corridors or across large outside areas, like the ice field on Karith.
2.The lucifer cannon's primary shot speed depends on how long it's been charged, with the less powerful shots traveling closer to the secondary shot's speed.
Increasing shot speed is the best change here. What I don't like about gpp luci is that it's too luck based if the human isn't next to the alien. Faster shots mean that being able to predict alien movements is better rewarded.
3.The flamethrower's damage decreases over the distance that the flame puffs travel.
I hope flamethrower projectile speed is increased so that it's possible to hit a fleeing alien. Also there shouldn't be any self damage from the flames or at least limit it to instances when the projectiles hit a wall next to human or similar. What would be fun is to make the flamer do damage over time in addition because it sets aliens on fire.
4.As pulse rifle shots travel, they slowly lose damage. Thus, over a long distance, it might be more practical to snipe alien buildings with a lasgun.
The pulse rifle isn't a particularly useful weapon in gpp. It's outclassed by chaingun against aliens and usually sawing buildings is better with s2 armor than shooting them with pulse. There are some exceptions of course like in tremor pulse is very useful when staying near either of the doors leading to the alien base and sniping builings with it. Note however that it's only good because the default alien base isn't well suited for aliens. Big open space is generally bad for aliens.
I don't mind pulse losing its long range capability because it wasn't too useful in that regard anyway. Making it competitive with chaingun against aliens would be interesting. Increasing shot speed would like in the case of luci increase how much skill affects the damage it can do. It would be a choice between hitscan chaingun that is easy to hit with and a projectile weapon where good prediction is required to make it perform well. Pulse rifle should be superior if the player can predict well especially because pulse rifle is a stage 2 weapon when chaingun is only stage 1.
5.What if you gained a dragoon barb after killing a human?
Aliens get evos for kills so compared to that it's not that strange but regardless I can't help but feel that there really is no plausible explanation for why the goon would gain an extra barb. Additionally requiring to make a kill to get a benefit isn't usually too useful. In public games most fights are 1vs1. In that case it's mostly useless. It sometimes can help in the next fight but it takes time to heal too and during that time barbs regenerate anyway. Against groups of humans maybe it can help more but i don't think the extra barb will affect the outcome too much. Usually either the aliens dominate the humans or vice versa. Relative positions of the alien and human groups is what really matters in this case.
6.Have the granger spit blur the humans vision like l4d's boomer bile.
Generally affecting players vision doesn't work well. It could even just be disabled by some players by changing settings. It's not really fun for the human either.
7.Allow players to sacrifice credits/evolution points for buildpoints. A running granger could get his just destroyed base back together faster by spending his 9 evo's he earned by not dying.
I hope you don't mean to increase max bp cap. If that is the case it would support killwhoring and potentially making the games not end when they should. It's possible that in a long game both sides could have so much bp that it's almost impossible to attack bases. If you mean just getting back bp that is in queue it's not too bad I guess but still it defeats the point of the queue somewhat.
In the end most of my thoughts about these could be pointless because the game will evolve but at this time I'm comparing the changes to the most current version of trem I know and thats gpp.