Does your lathe have a reverse ? I dont take my lathe out of gear once ive done the first pass. I put a clock on the toolpost go in 5 , do a pass, stop machine, then retract the toolpost to 5 past zero and reverse. Then start again +5 from the last pass.
I have a few spare 14tpi full form tips if you would like one.
For the bottle threads i just use a split die in my tail stock doodaa.