1. I would not drain any fluid out of the clutch reservoir as apart from introducing more air into system (both brake & clutch) and making bleeding much harder it will simply prevent fluid dripping out of the cmc supply pipes outside the bulkhead. This is easily remedied by sealing top of of master cylinder and capping off the pipe ends (where they meet CMC).
2. You need to disconnect both lines (at bulkhead where they join at cmc) and cover ends (next time I go to a scrap/breakers yard I will be sticking a few bleed nipple caps in my pocket lol) ..as you rightly said this will prevent fluid loss. A miniature "pick" set comes in handy when disconnecting the clips...........if you compare your new CMC you will see two grooves beneath the clips where you can get a small blade beneath clips to release them from your old CMC.
3. Not sure if bleed nipple is exactly in same position on US but I found the nipple easier to see and get to from the bottom of the car.....just raise the car and look on the bell housing (clutch side)...it will be adjacent to the clutch supply pipe.
4. Whichever method you use to bleed clutch make sure you keep the reservoir near max mark (have someone else continually topping up as it drops)