Hi Ray,
For keeping fretting fingers covering the string it is practise, practise, practise! slowly at first, don't try and go too fast. I think practising with a metronome is essential also.
I really like the squire vintage modified. It came with an updated bridge from the previous owner, a Gotoh. I have recently upgraded the pickups to Bare Knuckle hand wound J pickups. The sound is excellent now. I have had zero issues with earth problems with the original pickups or the Bare Knuckles. It is a really nice bass.
I am a Warwick fan, I think they sound great. Not to everyones taste though. For a bluesy sound I don't think you can wrong with a Fender precision. I am playing in [url="http://www.pointblankcornwall.co.uk"]Point Blank[/url] at the moment. I have been with them for a few months after coming out of a 5 year retirement from playing any bass at all. The set list is classic pub rock covers. We have good fun and don't take it too seriously.
Dean.