Your batting average is fine, it's my machine that has a bad average. Nope but I can do that.

Not really, these things happen all the time.  If a plane crashed through the roof and crushed your machine, but would be bad for the machine!.

Quite often transporting machines can identify small little issues like this.  I've done more reading about your sound issue and I reckon Humpalot and Mark's techs are on the money.  Easy job to swap the board.

The magnets, could be a number of issues, something simple like a fuse, or a plug come loose or maybe not.  I'm sure Nino would have it up and running in the time it takes to make a cup of tea, if you havn't sorted it by then.

 For me playing the games is fun but keeping them running and maintainance is also fun.  You've learnt heaps already this week and you'll know more by next week.  When you get your next pin you'll have more confidence to fix minor issues without hesitation!