US05 is notorious for being slow to flocculate, from what I have read, even more so when kept and re-pitched. Drop the temp as cold as you can without freezing the beer and it might help.
Craigslist for that price range. You should be able to get a good one with that budget. Brand new, you really need to be 1k plus to get one like you want.
Best practice is to watch how much you drink. If you question this see the thread about falling into a boil kettle..... I wait to throw a few back until after the boil, while things are cooling.
Restriction on the outlet side ant an issue, just on the inlet side. You should be good to go. Just make sure the tubes on your chiller are secure so you don't leak ice water into your wort.