So, I know that the cyberspace levels are getting an overhaul, but are you planning on keeping the textures? I know the existing ones are labelled as needing replaced, but what I mean by "are you keeping them" is using the same general textures, but better versions? Or are you going for a different look entirely? If the former, I can put together some nice looking cyberspace textures by reworking the existing ones to make them not suck.
Those are going to be tossed entirely. Hacx 2.0's got a much different (and improved) look for Cyberspace, since the old textures looked like puke in pretty much all circumstances. To be clear, the "replace this texture" labels are actually meant as a signal for mappers to remove it in any maps they may be working on that have it. They'll be erased from the wad entirely once it's done.
Most enemy sprites could certainly use some improvement, if you're willing to give it a shot. I've seen some nice Android and Buzzer improvement concepts but they haven't evolved past a single frame or two. Just don't mess with the Mecha Maniac or Terminatrix just yet -- I'm doing some tweaks to the former and the latter is probably going to be replaced at some point.
I'll see what I can do with the enemies, but in the mean time, I threw together this tweak of one of the jar sprites. How does it look (as proof of concept)? Note that it currently doesn't do well with the palette.