Good morning Mike,
1) I've experienced the same thing. I think this is because of the load caused by the weight of the sail and wind. They shouldn't come out of the track though. If they're coming out through the gate, it is too far open. If they're actually pulling out of the track, there's something wrong...perhaps a sail with too small of slug.
2) Everything you've mentioned are wear items...so they could wear out. However, the life on them should be pretty dang long. If in doubt, I would find a sailmaker who sails out of your marina to take a look and let you know what you're dealing with.
3) Again, I would make sure you have the correct slug for your mast. For instance, I have a Kenyon 4060. There are only a couple of slugs that Kenyon says will work properly with that mast. Perhaps you have a mismatched sail. The bright side is that having slugs changed out is a lot less expensive than replacing a whole sail.
Check out https://forums.sailboatowners.com/index.php?threads/poor-mans-mast-gate.143640/
There are a lot of blog entries out there on this, but this particular one gives some insight on what things are supposed to look like. Beyond that, check out www.mastgates.com.
There's a great solution to making raising and lowering the main single handed. I bought a mastgate from them and its great for that.
I hope this helps.