So, after 15 years of using Linux, I decided that my new laptop would be a retina MacBook Pro. I'm liking it a lot so far. It helps that it's a Unix system..
Windowshading (Rolling up to the titlebar) was in Mac OS in the '90s. But they dropped it in OS X in favor of minimizing. Back in the day you could get a Haxie from Unsanity but they died out with PPC. A lot of people didn't like how their hacks worked either because they injected themselves into memory and could cause problems. But for a long time they were the best way to customize your UI.
And in Safari, Command+Number switches to the top level bookmark of that number instead of the tab. I guess it's by design since it'd be less likely to change around. With tabs you'd have to remember the number of any given tab which could change at any time. But bookmarks would always be the same unless you change them yourself. I'd say try Safari for a while. You might get used to it. I can't go back to Chrome on OS X. Install SafariStand and EasySIMBL to get some features back too. (Just remember to re-enable SIMBL when an OS update happens. OS X likes to disable SIMBL when it is updated. So it's an easy fix when it happens.)
On OS X, all of Windows/Linux's Alt commands are pretty much replaced with Command+whatever. Command+Tab. Command+X/C/V/Z/F/G, etc.
OS X's networking is finicky I find.
I don't know about FLAC. I know I had to install an iTunes extension to get Ogg/Vorbis support a long time ago but don't even know if it still works because the music I needed it for hasn't been played in a decade. If it's even still in the library. Maybe there's an extension for FLAC but I don't know.
As for moving and resizing the window. I don't know about the first, but for the second you should look into BetterTouchTool. (Actually get it anyway) It will add so many features for you to play with. It's a must have. It might even help with some other problems you're having.
And look into some utilities called HyperDock and HyperSwitch. They add window previews to the Dock icons (HyperDock) like Windows has as well as to the Command+Tab switcher. (HyperSwitch) Not that it matters since you're from Linux, not Windows. But it's still pretty useful in some cases.
Welcome to the party! Just wait for WWDC and whatever 10.11 brings. It's exciting.