To #1: You can eliminate T and M6 output but.... your machine doesn't need any tool changes? and you do you use different tools? You can suppress it in the post file but I want to understand how your output needs to be and what you're doing.
#2: Find this line near the beginning of your post file under "General Output Settings":
arcoutput : 1 #0 = IJK, 1 = R no sign, 2 = R signed neg. over 180
Change the value to "0" like this:
arcoutput : 0 #0 = IJK, 1 = R no sign, 2 = R signed neg. over 180
That should change your arc code.
NOTE: Post mods can get you in a stick real quick. Always back up your post file first before making any changes. That way you have something to go back to in case you edit something incorrectly.
It's just a part..... cutter still goes round and round....