So, you wouldn't exchange F2F with a complete stranger, but with someone you've traded several times?
No, I wouldn't trade off-DEX with a complete stranger. I've traded face to face with complete strangers before, but always via a DEX where the bitcoin involved will be locked in an escrow prior to meeting to hand over the cash. But now a lot of my trades are done without a DEX because once you've traded with same person hundreds of times, you may find you have enough mutual trust to just message each other directly and send coins directly without using a DEX.
Yes, but they're part of the DAO, right? Don't the members of this DAO charge fees to sustain their operation? If there were more arbitrators, wouldn't this process be cheaper? If we're going to have complete free trade, the fees should adjust freely as well.
Bisq charges fees which are spent on funding the DAO and future development, yes, but arbitrators don't set those fees and I would be surprised if the number of arbitrators has any impact on the trading fees.
One more question that I can't answer honestly: can't someone fake their trust? Like, creates several Bisq identities and starts trading with each, to insure trustworthiness.
Bisq doesn't use a reputation system like that, so that wouldn't work on Bisq. Other sites such as HodlHodl let you view the profiles of everyone who has left a user feedback, so you can easily see if they are all fake accounts with only 1 trade.