Correct, get a TY-140 and hook it up to the PWM headers on your mobo.
Whats that when it's at home? I can only see a 120mm adapter with the 180mm fan in place. No 140mm.
Correct, get a BeQuiet BN188 and shorten the cables
Umm maybe, might get something thats made for us by Seasonic at work.
Who uses an HDD LED? But you are infact incorrect there are two LEDs evenly spaced between the single hole if you unplug your power LED you will see the HDD LED flickering away but seriously who needs an HDD LED? If it really bothers you use one or the other.
Im just saying, @ £180+ this is something you'd expect to be sported or alike would you not....? I've enough lights coming out the mobo to worry on the case but I can't exactly say to a punter yeah it's amazing cos it's a bag of poop really! Some mods will be needed if kept!
Correct, sadly thats a fact of slimline drivebays I have yet to find a way of doing a stealth mod for one.
Other than sanding the thing super flat, double sided tape and some really thin 1mm max aluminum thats brushed and black then nope nowt can be done sadly!
Correct, see above re. PSU
Not just PSU, USB is over long, PSU is tight, headers for the lights, switch are OTT!