Thank you everyone for your thoughts - it's very useful!
Yes agreed support is extremely important. One of the things that we're trying to avoid is changing terms without notice. We got bitten by this on various exchanges.
Yes @Patatas agreed, it won't be completely p2p. It'll be a bit like an escrow service I suppose - a place to make offers and bids, but ultimately you're dealing with the buyer/seller but with our platform to ensure trades go through .