I could voiceact the soldiers' logs for you, this is only a small effort since I have the stuff set up already. I'm sure others have a microphone on their computers as well, which is really all that's needed. If you can Skype, you can voice act.
I could contribute at least a small thing, after failing to deliver maps
This type of thing is a lot easier to do than voice acting
monsters, which is one of the more difficult parts of RMQ and one part we got a lot of flak for. But reading a short log entry into the microphone isn't difficult at all. More sounds make the game a bit deeper, especially on the story front. I really liked the log entries.
As for the Steven Hawking problem, there are ways to make spoken stuff more deeper and fuller IF the source recording is reasonably well spoken.
For comparison, the grunts, enforcers and ogres in RMQ are completely voice acted by the team. Of course that can always be done better, but - people who get worked up over voice acting in Quake mods should be a little more realistic. It's all done for the love of it.
About difficulty, yes, that's a hot topic. Just wait till Lardarse shows up (aka "Are you guys insane?!"). I agree that skill dependant monster behaviour is the right way to go. Sounds like you're on a distinguished road
Petty criticism aside, Hellsmash is outstanding.