Bisq Is an open-source distributed exchange, you should check it out. I'm not sure about the other ones but Bisq is pretty much the largest P2P exchange I know of.
bisq is safe or not
if iam use bisq service , dev can attack or hack my exchanger site or not
where i can see bisq demo site, iam visit not found about demo exchanger site or here
https://market.bisq.io/ , but not found about member area or admin area