"Oh yeah, what type of machine uses 100TG collets? " It is just another collet system for holding tooling. If you have a TG100 collet chuck, then you can use TG100 collets. I have about 6 BT40 x TG100 collet chucks (came with my VMC) and two sets of collets. I have NMTB40 x OZ25 for my Cinci Toolmaster, I have an ER32 system for the tool grinder, 5C collets for the tool grinder and the lathes, U2 and SK40 collets for the little mill, even some NMBT40 collets for the Cinci, . . . . and so on. There are many collet systems, try to standardize (ER40 is a good choice) but when the opportunity for cheap tooling comes your way - don't pass it by just because it doesn't currently fit.
Since you have an ER40 set up, go with it. Put the TG100 holder in a drawer for a future opportunity.
I can't help you with your power feed quill. Mine works fine, so I have not messed with it. Are you sure that you have the hand lever shifted all the way over?
Let us know how you make out. David