1: Devolution: The aliens may devolve but at twice the evo point cost. Without an overmind it costs 4 times as much.
This means to devolve from Tyrant to Adv/Dragoon would cost 2 Evo. (meaning, to either advanced good on regular goon, devolving from adv goon to maraduer would still only cost 2 evo)
To Devolve from a Tyrant into an Adv/Goon would cost 2 evo.
To Devolve from Tyrant to Adv/Marauder would cost 4 evo.
To Devolve from Tyrant to Adv/Basi would cost 6 evo.
To Devolve from Tyrant to Adv/Granger would cost 8 evo. (devolve to goon then devolve into a granger).
Dretches may not devolve, and no other life form may devolve into a dretch. Additionally, the dretch is in the same class as the granger, so it requires no more or less evo points to devolve with. The minimum for a dretch to devolve into a granger would be an evo into basi (2) then a devolve into granger (2) for a total of 4 evo which couldn't be performed unless the overmind was up.
Say you're a tyrant and your entire base and team is hosed and you're the only one left. Without an overmind, it takes twice as many evo points to devolve than before.
To devolve into a granger from tyrant would require 18 evo. As a Tyrant with 9 evo, a blown base and no team, you'd first need to devolve into a marauder (

, get 8 evo then devolve into an advanced granger.
2: Barricades.
Barricades should consist of 1 spike, not 4, and should have about 1/3rd the hp they have right now and require 1/3rd the time to build they donow as well. Each would cost 2 BP and be mountable on the celieng and walls. This would allow them to be built to the shapes a team would want but still be only able to stop a human team for a short period of time as they would be very weak against gunfire. Each barricade piece would have 60hp and be easy to destroy with virtually every weapon.
Additionally, barricades built next to eachother would reinforce one another, effectivly increasing neighboring barricades hp by 25% per barricade in proximitry.
2 barricades next to eachother would each have 90HP and in total, 180.
3 Barricades next to eachother would have 120HP and in total, 480.
4 Barricades next to eachotehr would have 160hp each and in total, 640.
5 Barricades next to eachother would have 200hp each and in total, 1000hp.
6 barricades next to eacother would have 240hp total and have 1440hp total.