Fermentation time depends on many factors including the yeast strain, pitching rate, available oxygen and nutrients, temperature, wort composition and fermentability. Fermentation is done when it's done, regardless of how long you want it to take. Let it go until the Krausen recedes and then allow 3 or 4 more days. Refrigerating after that will speed up the clearing you want before bottling and may cut a few days off of the overall time.
Yo, 100% agree. I brew beer in Australia just to save money, so I don't wait to 'condition' my beers. After FG is reached, all you are really doing is cleaning up the beer. The yeast continues to slowly eat, and this creates a cleaner tasting beer. If you're like me and don't mind a Hazy, and even prefer them, don't worry about conditioning 3 weeks.
The longest I go is probably 2 weeks. Everything depends on how active the yeast is. Like
@BOB357 is saying, your Krausen is going to tell you what stage you are at. Once you hit FG and the Krausen begins to dissipate, the more patience you have, the more it will clear the beer up.
In my opinion, there isn't a right or wrong answer to this question, FG is FG, and any arguing beyond that point is personal preference, with the exception if the beer is being judged. Most of us here are just brewing to enjoy, not become Brewmeisters, not that I would turn that opportunity down though!
Oh, and he's 100% right about cold crashing too after your fermentation is done, the beers that I cold crash taste better, but I don't always have the time!