is counterwallet site consider a web wallet ?
That's an exception.
The validator can SPOOF the buyer or seller and default on their obligation after getting a valid signature.
No.
Would love to see Nemgun and dzimbeck cooperate and discuss this issue at length. If there is a serious concern, may be dzimbeck can offer some sort of consulting during dev. Any thoughts?
If said user wanted to review the project and give input, they would have contacted nemgun (for example) directly. Said user is not likely interested in that, but has a hidden agenda.