melly

I need some help! I took my 84 Z28 to the dealer (didn't know where else to take it, limited selection of mechanics in a small town)
On a trip in, it was brought to my attention that there had been 3 recalls on my car and they could fix them at no charge as they bill GM Canada. Since my trips to the dealer has begun I have had so many things go wrong with my car I'm almost in tears. I was wondering if anyone can help me (not at all mechanically minded) to explain what these recalls are and if any of the recalls (if improperly fixed) would contribute to some of the new problems?
Problems:
Thermostate not working
Car stalls on a cold start
Squeaky wheels
Horrible loud noise under the back of the car (which the swear is the catilytic convertor)

1-Evaporative canister purge thermo vacuum switch (tvs)
2-Rear disc brake cone clutch park brake adjuster ( they used a caliper actuator to fix this and had to replace the RR caliper due to it being seized & pitted & could not be overhauled)

Thank you for any input!