* Please Critque my Plumbing Design

[GRJack]

I'm finishing the upstairs to my loft above the barn (separate building from
my main house). There is no plumbing there now.

Please look at these 2 designs, tell me which one (or neither) is good:

A few particular questions:
* It will be a sob (but doable if absolutely needed) to run that long vent from
the kitchen sink to main vent stack in Plan B - will the AVV in plan A work?
* Since the toilet and lav are so close to the stack do they need a
separate vent - is the 4 1/2 feet distance on the lav within 'critical distance'
to stack so I won't need a separate lav vent, or do I still need one?
* Is it ok that the vent stack and the sewer stack are offset by approx.
9 inches (vent stack is to the left of sewer stack, so will it be able to properly
ventilate toilet?

Thanks in advance for all advice.