I'd rather save $100 and buy a hero, unless you want the 'thermal armour' look. If you really need bluetooth/wifi there are plenty of intel pci-e solutions that will cost a fraction of that, function better and don't neuter the best feature of Z97 with a 60mm only m.2 slot.
There is nothing scary about direct-die other than the fact removing the IHS can be a pain. Back in the day the best chips were direct die cooled, and you rarely had people cracking them. I kind of miss those days, 2500M was a beast.
FT03 Mini is a great case, and like most other mITX, requires hardware planning before blindly buying. That's the only knock against it, and it's nowhere near as flimsy as the N1 is.
All you're doing with vrm, chipset and ram blocks on a haswell platform is adding cost, restriction and more points of failure to a loop. It's for aesthetics only.
Do not use anything aluminium with direct water contact in your loops, period. Direct res options that are small are an EK d5 multi or the aqualis d5 100.
And FYI the Hadron rad is copper tubes with aluminium fins (totally fine)
It's not difficult, just make sure you're getting the correct firmware. This is slightly more involved on motherboards with integrated LSI controllers (like my supermicro X10SL7-F), but just as easy in the end.
Nice guide