I've got some shots of a phal I trimmed the roots on. I posted them in the water culture thread and haven't figured out how to post them here again. I'll work on that. Be sure to soak the roots for a good ten minutes or longer for the living roots to have a chance to absorb water and plump up and turn green. If the roots are gray and squish after soaking, they are goners. Sometimes roots are dark colored from the potting material or are algae covered, doesn't mean they are dead and roted. The gentle squeeze test for squishyness is the best test. I usually trim off broken roots too, as they will just die and rot. I wouldn't save obviously rotten roots just to use them as a support for the plant. Bamboo skewers pushed down into the planting medium with a twist tie holding the plant to the skewer works for support.
With the catt rooting out the bottom of the pot, I would cut away as much of the bottom of the pot as I could, then slip/pull the plant free of the rest. With your seedling catts, break the bark pieces smaller, mix in some vermiculite to hold a bit of water, or tear up some of the sphagnum moss to add to the mix for a little bit of water retention.