Re: buying a 156 - which one?
1. on a 1998 model there should be 2 keys, both red, both with remotes.
2. common fault, very rarely fixable even by dealers (DIY it then get airbag ecu reset). its usually due to a dogy connection under a seat.
3. full resprays are expensive if you want a good one, and personally a car is never the same once you respray it. touch up paint isnt really suitable in this scenario either (unless you're skilled). personally i'd look elsewhere, mechanicals are easily fixed, bodywork isnt as cheap or easy to put right, and it'll bother you every day.
4. 16v TS is very similar to the 8v TS, you should notice increased mpg and you can rev it more, but the difference isnt huge. in many ways i prefer the 8v, the timing chain makes getting to sleep easier and for a start.