Should be possible to do the turret via macro I would think.
That is how I have done mine.
Before I bought the control I enquired about getting my turret working and eventually I managed to explain how it worked, Mike kept thinking because it was servo I would need a 3rd axis. Anyway I got a macro, it wouldn't have worked but I was able to see how things were done and thus modify it to work.

A friend is currently putting the SZGH on his Beaver TC15 lathe and I have been helping out with it. His is a servo driven turret and previously I wrote a macro for Mach to work it as the A axis and it worked well. He ordered a 3 axis lathe control and it is a C axis that is used on the SZGH for it. The macro from Mike worked sometimes and other times wouldn't, we tried all sorts of things to get it working consistently but in the end we gave up and I wrote a new macro but with using G90 moves rather than the G91 Mike had used. It seems to be working fine now although he did say he had a fault today for some reason.

Shame about the spindle, do you have 3 phase? If not then maybe a rotary converter would be the easiest/cheapest as I wouldn't imagine it cheap to send the motor/drive back for replacement.