The squeaking wheel sounds like a sticking brake pad, as putting the brake on affects it. Going round corners makes the pads shift as the wheel tries to twist under load, so it would tend to confirm this. A dodgy bearing would drone, not squeak.
Drop the pads out, clean the rust and gunge off them and then replace them with copper grease on the backs and ends, so they slide around more easily and don't jam in the caliper.
Don't drive with the handbrake on - the calipers have a self-adjuster in them and you'll strain the mechanism (knacker it basically... new caliper @ £180 should help you remember).
The temperature sounds okay-ish. I'd change the thermostat as it should warm up to 90C and then go up to 97C before the fan kicks in. I think the 'stat is staying open, so the water in the rad is not getting a chance to cool before it goes into the block again (albeit the entire system is at 75-80C).
Normally the water in the rad' gets a chance to cool more if the 'stat is controlling the temp in the block at 90C as the cold water that just came from the rad' will need some time to warm up and the 'stat will close a bit while this happens.
So, your system warms up to 90C again very quickly... the incoming water isn't as cool as it should be.
The hesitation could be a Lambada.. a new MAF might not have been the culprit. It's unlikely that the part would fail so quickly. An emissions test will tell you if your Lambo is broken or not.
Your car is a rival for your missus.. it makes you more attractive to other women, so she is threatened by it, that's all. Buy her some flowers and tell her to stop whining.