I like the spirit of the idea, but I'm not sure it should be standard-release but instead maybe a mod.
I think it could be simplified by permitting a TEAM VOTE to grant/revoke "Chief/Master" Builder(s). There could then be several levels of BUILD MODES that specify levels of lock-down of building such as BUILD_MODE_OPEN, BUILD_MODE_NO_DECON, or something. A Master Builder can set the active mode for the team. Certain 'sensitive' activities like deconning by a regular builder under BUILD_MODE_NO_DECON won't execute until approval is given by a Master Builder (through like a 'approvebuild'/'rejectbuild' command they could bind). An automatic approval can be obtained after like 10 seconds so that desperate builders aren't totally at the mercy of a Master Builders alertness.
Only Master Builders would get messages and prompts for approvals so as to not bother the rest of the team. Certain special cases would need to be covered where the mode would automatically reset to BUILD_MODE_OPEN if all Master Builders disconnect, timeout, idle, SD, "Overmind Needs Spawns", or something.
Again, the Master Builder system doesn't even HAVE to be used. It's team optional.
Other Master Builder idea extensions could be to give a bp quota to individual builder (a forward base builder), set a max limit on the number of some structure ("no more than 8 eggs", "No more than 2 DCs"), prevent some structures from building ("No barricades, please"). Master builders (or maybe builders in general) could receive more detailed info about damaged/destroyed structures ("Turret #12 Critically Damaged") that may not interest the warriors.
I know any similar scheme is complex, however building is crucial to the game's procession, and large-scale servers with many good regular players would likely demand some sort of enhancement in this area so they can actually have a chance to enjoy a good competitive game.
Yes tools already exist to assist in designating builders like kicking bad builders and voting for a map restart... but how much of that can you really do and have an enjoyable game? Several have commented that griefers aren't that much a problem, and I for one disagree. Almost every good game I've had was ultimately ruined by griefers to a percentage of perhaps 70% I'd say. The frequency and impact of the griefer problem cannot be assumed to remain constant or insignificant either.