I go to my local trailer shop once a year and have both hubs replaced with new ones. I keep a couple of spares rebuilt and lubed and in large ziplock bags in my toolbox. Once I had to replace a hub along side the road, it took me probably 30 minutes from start to finish. I didn't have to break down the old hub, just pull it, clean/grease the spindle and install new hub. A cordless Dewalt drill with a socket that fits lug nuts works wonders for snugging the lug nuts, then just use the lug wrench and/or torque wrench.

I would at least get those bolts free and replaced. Hate to have them seize on you when you need to change a tire. The wheel looks pretty bad, probably structurally ok, but better safe than sorry. I would replace the hub and the bearing buddy.

btw, the "bra" for the bearing buddy is to keep from slinging grease all over your boat in the event of a failure/leak, and to keep water and debris out.

I would replace those studs. It's a real bummer when they start busting off while your totin it down the big road. Replace the bearings and races, they are cheap insurance. as far as the wheel goes, if it aint cracked, bead blast it and repaint it.

What does it cost to have both hubs redone?

Most places charge an hour's labor, plus parts. $80-100 bucks normally.