What should be done if anything about roots growing thru fabric pots?

Nothing you can do, or needs to be done. They will die a natural death due to being exposed to light and also drying out and will not effect your plant adversely. More or less, think of it as a weird way to prune the roots. The roots will die, signalling that going any further in this direction is a no-no, so will branch off and grow into the yes-yes territory inside the pot. If you are really keen and have the space, placing the pot on top of a larger container containing new soil as what is in the original pot, will boost growth by giving the new roots somewhere to grow into and with fresh substrate, a boost to vitality. Beware of bag seeds though, they are most often the result of female hermaphrodites, meaning seeds produced this way will have a genetic dominance for being hermies themselves. Far better to buy fems with known and stable genetics from reputable breeders. Also mixing autos and photoperiod plants in the same grow is never ideal, your photos won't flower at 18/6 and your autos won't yield very much at 12/12. Much better to grow all autos or all photoperiod plants if you only have one grow tent and is the only realistic option. Hope this helps,.......... Organoman.