5. Accumulator freezes up when charging- high side line after the expansion valve also freezes up but no coldness enters or exits the evap core. BUT both lines to the core have been disconnected and compressed air blows through freely with no apparent restriction.
This can be normal when charging to the high side. The cold is created when the refrigerant expands. It is common to get cold at the fitting it is being put in at as it expands into the empty system. It is better to charge through the low side because if the pressure on the high side goes up as it should, It can prevent the refrigerant from moving from the can to the system and the can could rupture if the pressure gets too high.
6. AC line to and from the compressor are NOT hot when AC compressor clutch is running.
Only one should be hot. The other will be cool. Hot is high pressure going to the condenser at the front of the car. Cool is the low pressure intake from the evaporator.
7. Hooked gauges to high and low side and ran compressor. Both read 110 with compressor off- but BOTH increased to 125-130 with compressor cycling on.
Are you closing the high side pressure gauge valve? The gauge manifold has a knob on each side. You should close them unless charging and then only the low side valve. If they are both open the high pressure can migrate to the low side negating the system.
When a gas is compressed it get hot. When it expands it gets cold.
The orifice tube/Expansion Valve is basically a small hole (restriction) with High Pressure refrigerant on one side. The refrigerant escapes through the small hole and the pressure drops creating cold in the evaporator.
If the High and low pressure is too close to each other, then you have a bad compressor not creating pressure or the orifice tube/expansion valve is defective and not creating a restriction and it will not build pressure.
If the Orifice tube is clogged it will build very high pressure on the high side and very low pressure on the low side.
You mentioned you added 3 oz of oil. You also mentioned a remanufactured compressor. Some will come with oil and some will not. Did you check the compressor for oil?
I do not know the specs off the bat but that system should use about 6 oz of oil. check the label under the hood. You need to be sure that the oil is correct type and amount.
You said the compressor was a reman unit, how did the old one fail? A bad clutch will not send trash into the system but if the compressor was making noise then it was coming apart inside and probably sending metal filings into the system.
When you replaced the compressor what color was the oil coming out of the system? Clear or green is okay, Green is a dye some people use to find leaks. Grey, black or any other color is metal in the system and you have to do a serious cleaning/replacement of parts.
When replacing the compressor you should do the following.
Flush the hoses and evaporator. Take note of the oil coming out.**
Replace the orifice tube/expansion valve.
Replace the filter/dryer/accumulator.
If you have the modern style condenser that can not be flushed replace it otherwise flush the evaporator and the condenser.
How many of those things did you do when you replaced the compressor?
** If the oil shows metal filings you are bettor off replacing the evaporator & condenser unless you have a professional flushing machine.