Carpet - My carpet has come away slightly ob the drivers side, if you can then try to clip it back into the black trim that keeps the carpet in place, have a look at the other side if you're not sure what I mean. If this fails just do what I've done and super glue the bugger down.
Computer/MFA - Sometimes they just play silly buggers, so try taking the fuse out for a minute and placing back in, if this fails just disconnect the battery terminal for a minute or so and see if it works. If it doesn't then there's a different problem.
Rust - Goes without saying, get it done and sorted asap either by yourself or a good bodywork specialist.
Ruined alloys - Easy peasy, send them to a good refurb place who will have them looking like new, I can recommend these guys -->
http://www.gstar-dubworld.co.uk/ as the owner Tesh posts on here and is known personally by a lot of us. jv had his refurbed by gstar and they came back looking mint and compared to what they were like before the refurb it was as if they were another set of wheels.
Seat bolster - Not sure, probably best to see a good coach trimmer to see what they can do and depends how bad it is. I've not used this but a few forum users have and said that liquid leather is really good, website here -->
http://www.liquidleather.com/Hope this helps.