What's the repair
It is a pretty straightforward repair if you are somewhat handy and have the right tools. You will need: Electric drill with various size drill bits, 1/8" punch and hammer, 3/16" diameter stainless steel rivets, a rivet gun, and silicone caulk.
Drill the heads off of the rivets which are holding the mast base casting into the mast. Then use the punch and hammer to knock the rivet shanks into the mast. Pull the mast base out of the mast (may need to be knocked out with a hammer and a block of wood if it's tight). Place a thin film of silicone caulk around the new mast base and insert the base into the mast. Using the existing rivet holes in the mast as a guide, drill 3/16" diameter holes into the new mast base for the rivets. Install the rivets into the mast, sealing them with silicone caulk.
It is a one-hour job, tops.
am I better off never stepping the mast and just leaving it up all year long?
You're better off coming up with a safer and more reliable method for stepping the mast. If your method allows the mast to swing from side to side out of control, then it is definintely not safe and you're lucky that the only thing that was damaged was the mast step. The Getaway mast is relatively light and can be handled easily by one or two average sized adults. I recommend having someone help you and that you step the mast manually with two people. If you don't feel comfortable stepping the mast manually, Hobie has a mast stepper kit that allows you to safely
raise and lower the mast mechanically.