I'm surprised nobody's mentioned pee-stain removal products. Google cat urine removal and a bunch of good info comes up.
I've had cats my whole life, never declawed any of them. I'm glad it's illegal in the UK, though I wonder how that came about, but IMO it should be illegal throughout the world.
I've had bags pissed on by my roommates cat warring with my own cat for territory and basically the bags were ruined as the pee-stain had set.
If, however, you get to the peed on item while it's still fresh you have a chance at cleaning the item (gig bag etc) effectively.
Don't use ammonia, or ammonium, to try to clean cat urine stains. There are several commercial products available that work well, but the best I've come across is
Urine-Off.
Cats pee for territorial reasons (like when we got a new cat) or to tell you they're pissed off about something (like on your shoes if the cat box needs cleaning).
Currently my wife and I have two rescue cats that we took in. First we took in one, then found the other almost a year later. It took two weeks for the hissing howling pissing matches to die down. It was two months before they tolerated each other.
Two years and a move later and we have well adjusted cats that play together, and don't mess outside their litter box. Now they just tease the dog... They use my gig bag and my EA backpack as sleeping areas and scratch pads, crawling inside if they're empty and open (it's a DB gigbag, plenty of room for everyone). I've never had my doublebass knocked over by their antics (chasing each other, footy (*soccer) w/ paper balls etc, though this is a potential hazard.
Oh yeah, there's also commercial sprays you can get that are meant to keep your cats off the couch and or curtains. They cost a lot and you have to reapply frequently. Don't bother, just use some essential oil, mint as was already suggested.
Finding a socialised cat is easier said than done. Hold the cat, turn it upside down like you're cradling a baby. Does it struggle to get away or let you hold it like that? If it let's you hold it like that it may just be in a good mood and vice versa.
Cats, like dogs or humans, have individual personalities — some are just jerks. Right now one cat is asleep on my pillow, our other cat rarely sleeps with us, but they're both sweeties — I've yet to meet a person's pet snake that had any personality even though my friend's snake, Fluffy, liked to curl up on my head amongst my curly locks.
Sorry for the long post, but I'm Cool for Cats!
) I found this great chart to identify house cat coat colors and patterns. 
