Welcome to ATP, Pat.
Let's start all over with the potting. I grow all my jade in clay and the size of the pot is determined mainly by the size of the plant. I would need to know more (let's have some pictures!) about the plant to suggest a pot size. You can either use "cactus and succulent" mix and that will be available at most big box stores or just custom-make your own. I use 1/2 general purpose potting mix, 1/4 coarse perlite, and 1/4 medium Douglas fir bark for my jade medium. The main goal is to have a medium that retains some moisture but drains exceptionally well. Water that potting mix but allow all excess water to drain from it so that it will be moist but not wet. In other words, you want a slightly moist mix ready when you re-pot.
I would remove every bit of "soil" from those roots. Leaving the entire root ball under water for 30 minutes should either drown those insects or force them to float up to the surface of the water, where you can get rid of them. I don't like using insecticides on weakened plants, but others will differ on that. When you remove that jade from being submerged, just leave the jade in the sink. Then spray it down thoroughly with tepid water (hopefully, you'll have one of those spray facets at your laundry room or kitchen sink). If there are any insects left (probably not), that spray will rinse them off and down the drain.
Do not fertilize and do not water. I would wait a week or even two before watering, and even then, I would only water the plant lightly when the potting mix looks very dry. Until those roots have regained their vigor, they can't utilize much moisture and certainly not fertilizer. It might take a month of this light watering (but only when the soil really looks dry) to see some growth. Don't be impatient. When you see new growth, go ahead and fertilize with 1/4 strength, general purpose fertilizer. That will probably be 1/4 tsp./gal. I subscribe to the phrase: "Weakly-weekly". You don't want to fertilize weekly, at least not a jade, but you can fertilize at every other watering when the potting mix is dry.
Good luck and let's see some pictures.
