About threading left to right. I have never done that. For breech plug threads in barrels that would be handy.
Is the lathe run backwards, with the tool upside down?
On my day to day lathe the chuck is held on with threads. Any problem with the chuck unscrewing?
Upside down and backwards, yes.
I have also started using 90 degrees and feed straight in. Using 60 degrees, you may hit the shoulder when feeding in.
My last 7/8-14 was done at 90 degrees and looks great.
I have a screw on chuck, never loosened.
My 1937 South Bend doesn't have a brake either, it just coasts to a stop.