Sign at the Kite Lake says that one must stay on the trails to Mount Lincoln, Democrat and Bross otherwise one is trespassing and a sign a couple feet away says that trail to Mount Bross is closed - sign looks very recent - so is it indeed closed ? and will I indeed trespass if i dont climb Mount Democrat on the standard route?

https://www.14ers.org/peaks/mosquito-range/mount-bross/ guess should have googled - so mountain is indeed closed !

Perhaps some people from Colorado can comment more accurately but when I was there in 2015 there were about fifteen people at the summit at once, with four ATVs parked within spitting distance of the very top with local riders. From what the locals said there are numerous property owners on the mountain and not all of them are on board with letting people access the area, thus the sign at the base. However, on any given nice weather day in summer several dozen people traverse the summit, so take the sign with a grain of salt. If you wish to obey the sign and avoid the very top you can still take the trail from Lincoln back down to the TH to complete the loop as it does actually avoid the summit by a substantial margin and that route is perfectly okay with ALL parties concerned.

Just go. Nobody up there is going to tattle on you, and nobody up there has any authority to tell you otherwise. The signs are merely there for liability reasons.