How about making more than one spot for the Traitors to C4 the pipes so to speak, with each additional burst resulting in a higher level of water? If the water does deal damage it should be relatively small (Or even ridiculously small, like 0.01, but doubling w/ forgiveness, so for the first few seconds it deals no damage, then starts to rape you), and the poison damage type (Only problem is the screen fuck that type does :P), so getting stuck in a bad spot won't completely fuck you over, as getting out will see some of your health back.
Other random ideas, uhm, how about that genny being interactive somehow. Like having the genny toggle-able turning on/off indoor lighting or some such. And when the water reaches the genny have it explode, permanently killing indoor lighting.
Also, add a melon in with the heli-mines, because every map needs melons.
An interesting idea would be being able to see a dead players scoreboard tags on searching their body, although it would probably be a bit cluttered, so maybe randomly choosing a marked player or two with a little message like "Player1 considered Player2 an Ally", "Player1 suspects Player2 of Treachery", etc. in a new tab in the corpse check. I'd love scrounging bodies to add to my suspect list. Although I think the tagging is just client side right now.
I'm loving the tagging system btw.
On another note, I think the C4 should leave behind a large scorch mark, mainly for cosmetic reasons. If it doesn't already... it might, I'm not the most attentive person, but I'm pretty sure it doesn't. It'd be fun to see a large "crater" in the center of a room with some poor saps corpse stuck in the rafters.