Re: 147 problems
sadly i think you've just probably being sold a lemon, this could hve been any car, the fact its got an Alfa badge on the front is irrelevant. I've got a 147, & can tell you hand on heart that over the past 8 months (10k miles) she's been brilliant, but mine is a much lower mileage (48k), hard to say what to do, i'd stick with it, buying another used car could just lead to more money all over again. It also sounds like the garage you used has gone into overkill to sort a few problems. let us know what you do. but if you do keep the 147, you've found the right forum, as i've found myself many a time, what some people on this site don't know about Alfa's probably ain't worth knowing!
BTW buying any car with 100k miles on it is taking a chance, natural wear & tear happens.
146, 147, 156, 164, 166, GTV - This is becoming a bit obsessive!