Hi Dee,
I think it's a two part question :
- how do you intend to use the .mobi suffix ?
- what is the quality of the locations ?
Personally I would rank .mobi quite a long way down the list, but that's a subjective view.
As for the locations, you have an interesting mixture. Wolverhampton and Colchester are solid, fairly large places, NewcastleUponTyne is arguably the best but many people would prefer the shortness of just Newcastle, Wembley has various positive sporting and entertainment connotations besides being a fairly bland northwest London suburb, the minuscule and rather anomalous St David's probably merely happened to crop up in searches for free-to-register UK cities and Fulham has a mixture of pluses and minuses as a quality London suburb dependent on how you use (and bound) it.
Whatever the merits of some of the locations, though, I think the biggest issue is working out how to use the .mobi suffix in these contexts.
David