yes rigel a proper usable functioning p2p exchange is the way forward and i'd go as far as saying is a crucial element in keeping cryptos on the decentralised path.
There has been talk of P2P exchanges for a while but so far, none have caught on. Most of it still seems to be confined to theory at this stage with few, if any practical examples to show for it.
Like Monero is a fork of Ducknote (Bytecoin), probably a fork of NEM vould be more successful especially if ran by somebody who knows how to hustle and market.
Monero wasn't a fork of duckNote (now rebranded as DarkNote). Rather, both coins were forked directly from Bytecoin. A NEM clone probably wouldn't be very successful. NXT has had a few clones and most of them have failed despite the fact that NXT also has the added disadvantage of (percieved) unfair distribution and lack of marketing skills.
Additionally, NEM still has the unfair and incorrect perception of being a NXT clone despite having had an original codebase for quite some time now. A NEM clone would be viewed by many as being a clone of a clone.