I'm helping with the electrical in a newly built guest house. We are
running into questions, especially with feeding the guest house.

Guest house is:
1200 sq ft with interior, and exteriour lights, cieling fans. kitchen,
bath, dishwasher, disposal, AC, heater, and about 20 outlets. Only
thing that is 240 volt is AC unit.

I'm saying we need at least 100 amps from the main (which is 200
amps).

Previous "Electrician" ran (before guest house was built) 3 - 6AWG
wires (2 hots, 1 neutral) to 2 - 50 amp breakers in main (which he
left HOT with black tape on the ends! Idiot!)

One guy says that 2 - 50 amp breakers is 100amp (on 2 phases) and we
should be ok

I say that we need 2 AWG wire (based on asking around) for 100 amp
240 volt service.

Besides "Call a real electrician" , can anyone offer advice on feeding
the sub panel.

Yes, it will be inspected.

David