You did indeed pretty much hit all the points.
It also depends on what year your 200 car is... if it has the TXV and therefore the thermostatic control instead of on/off switch on the dash, then you can control and limit the clutch operation so as to avoid evap freezing.
Anyhow evap freezing only happens if your A/C is running in top performance...

R134 in a 240 vol owould't be great mostly due to the condensor efficiency and the lack of airflow through it (cooling fan).
I wold also suggest R12, or if youo do not care too miuch for the compressor (or are sure there are no leaks), consider freeze12. I put that stuff on my 89 mustang 5.0 and its ice cold three years later now, very happy with it, and you can buy it cheap anywhere.

I also remember that the late 80s 240 had some sort of muffler / silencer at the line between compressor and condensor I think, it is in front of the condensor behind the grill, it tends to rust out and leak. A replacement line eliminates it completely, yoou do not need it.

As for the TXV screw, serioiusly avoid touching it UNTIL everything works and youo only have tweeking to do.

Good luck!
Greg Mustang
Montreal - Canada