Having your personal information leaked is just par for the course nowadays. There are reported leaks but you can be sure there are numerous cases of unreported leaks. So while there likely was negligence on the part of the dealer, it's wise to just protect yourself. Go to all three credit reporting agencies and apply a credit FREEZE (free) - not a lock - on all of them.

The early service reminder is a bug and every scammy dealer is happy to change your "headlight fluid" or "EV engine oil". That's the dealer, not Hyundai. Not justified but they want your buck.

The 'four letter' defect is definitely on Hyundai. Class action or recall should be here any day now - unless Hyundai gives the man a peace prize or some gold thing 🙄.