2002 Hyundai Santa Fe Alternator problems

We bought a 2002 santa fe last year and it now has only 20K miles. We have had repeated problems with power steering fluid leaking out, getting it fixed, leaking again, etc. 2 days after last fix, the noise when making turn started to return. There was still power steering fluid. Next day. Suddenly all the lights on dashboard started flashing and then car went totally dead.
Had it towed to dealership (we are on an island. Not many choices for repair). They said alternator was totally burned out.
Is it strange for alternator to go this soon? What could cause it to burn out and is there any connection with the power steering problem we have had off and on for months? Another curious thing that has happened from time to time is the radio suddenly turning itself on. I saw on another forum others have this problem. About 6 months ago we replaced the battery. Being on a caribbean island we are told batteries don't usually last more than a year here. But perhaps all the problems we have had are related in some way? We had to search the island for an alternator since the hyundai dealer didn't have one, and finally found 1 available, today, for $500 (ouch!) We bought it and as I write my husband is taking it over to the dealer. Any advice? Very much appreciated. How do I make a donation?