Yes, Epsom salt soaking is often recommended. I would try that for a few days before resorting to Tricide Neo, Penicillin, or another antibiotic. Unless, of course, you feel differently.
Yes, that looks like bumblefoot. If your hen isn't having trouble walking, it is not a bad case...yet. I've never had to treat bumblefoot myself, but I've heard about injecting the foot with Penicillin to kill the infection. Sometimes oral antibiotics work, too. And of course, you could...