Not unless you like the idea of destroying your AC system.
No.
No
Is r-22 Freon compatible with r-134a freon?
Your AC won't work any better than it did before. Two very different refrigerants, which will not blend, with different superheat points and system pressures. Not to mention that R22 won't carry PAG oil through the system as effectively as 134a, meaning you could end up starving your compressor of lubricating oil, thus burning it out.
No, R22 is for refrigerators and home AC. It runs at a different pressure and you can't use one for the other.
No. the pressure are different, r22 runs at a fairly low pressure and you shouldn't be worried about blowing your gauges, but you won't be able to determine your super-heat or sub-cooling. for a about $100cdn you can buy the right gauges.
Unless your system has been convert to take R-134a you would need 25oz of R-12. If your system has been convert to R-134a you would use 20oz to 21.25oz of R-134a.
No
NO ! and Why?
The refigerant gas 134a is used in the evaporator and condensor and many brands of 134a contain ester oils, so yes.
R-134A is what you use to re-gharge the a/c system