So we just bought an '87 420SEL...Questions of course regarding the HUGE machine

[WANT '71 280SEL]

First of all, it drives like a dream. Almost as dreamy as my w116, but not by a long shot in my eyes. Anyways, here comes the questions.

1.) When activating the windshield washer, it only sprays but does not activate the wipers.
2.) The intermittent wiper setting doesn't work, related to #1 I assume?
3.) When the heat is on, it only blows cool air out the back vent in the center, is this normal? Even with the car on it's highest heat setting, it is still cool air coming out.
4.) Sometimes after starting, the car will squeal for about 3 seconds, this isn't the dreaded chain rattle is it? It osunds like a blet, but my dad wants to take it on a 5 hour trip each way and I just want to make sure.
5.) The ambient temperature display only works with the key turned to on, then it goes out either right after the car is started or about 3 seconds after it is running.
6.) The a/c compressor doesn't come on. I looked very briefly at all the fuses and they appeared to all be okay, could it just be that low on freon? Their are no stickers indicating that it has ever been switched over, and the fittings look to be orginal. Also, one of the a/c lines going to the drier behind the l/h headlight looks rusted, is that okay?
7.) Their seems to be a slight ticking noise coming from the engine. Are these known to wear out rockers or lifters?

The car has 173,000 miles and we DON'T know if the chain and rails have been replaced. My dad knows about the potential problem with the chain and doesn't think he has anything to worry about yet because, "they don't always break, I'm sure some people's last 300,000 miles. Wouldn't it have probably been replaced if it has lasted this far?

Thanks
David