Please help me as i continue my venture moving to the commercial side of the trade lol.

I am currently working on a maintenance with two of these units. I have a question about checking Refrigerant charge. These are two completely independent circuits, correct?

What is the correct procedure for determining if the units are operating properly?

Do both circuits need to be run at a higher indoor load or can i just check the circuit that is running, then maybe jump out the 1st circuit and run the second?
i had 3* SH on the first circuit and thats a little low.. I didnt do anything about it yet but all coils and filters have been cleaned. What does YOrk say?

Second question, when checking voltages and amp of three phase equipment. my blower motor was rated for 5.1a FLA and it was running at 3.4a the voltages were all different across the three legs..

That amps of the compressor differed 3amps from the legs. so what is my amps and or voltage wich one do i pick? i know i can have a certain fluctuation but when is too much?