Can you check my layout? True Bypass Looper w/ ABC

[klt79]

I was supposed to build 3 - 3 bypass loopers and an ABC looper separately but my friend offered to make me an enclosure that can house everything. Tried to search online to see if there are answers to my questions with no luck. I have no electronics experience, so please take it easy on me.

I'm also thinking of adding the channel selector/ amp reverb to the enclosure.

The questions:

1. Can they all share the same ground? (FX before the amp, FX in the loop, and the channel switch)
2. On a 3PDT, can I ground a bypassed pedal to a lug where the LED is attached to? Layout is attached.
3. I want a toggle switch that can put the effects in the FX loop before the 2 effects before the output jack. With the switch down, the signal goes: guitar -> 2 loops -> ABC w/ master bypass -> 2 loops -> preamp -> 3 loops -> power amp. With the switch up, the signal goes: guitar -> 2 loops -> ABC w/ master bypass -> 3 loops(from the FX loop) -> 2 loops -> amp.
4. Other than being flexible does stranded wire offer other advantages over solid core?

I thank all of you in advance for all the answers and suggestions!

layout is here: http://www.freeimagehosting.net/a584z