I met Sturgeon and Salmond before any of this, years ago, when I lived in Scotland. That's just anecdotal though. I came to knew, one through work and one socially, 2 SNP MPs who I'm pleased to see are free of any scandals, I would genuinely be surprised if they had been involved in any, though.
Wrt Salmond, if he was acquitted, then he is not guilty? Boris has been found guilty of breaking the law while in office.
I'm in Yorkshire and admittedly not an avid news reader, I tend to skim headlines for the most part, but I have heard of every one of those stories relating to SNP members, apart from Mike Watson.
Press coverage differs because Westminster has more power, and is responsible for the entirety of the UK. While I think it is (mostly) relevant to all of us, there won't be as much widespread coverage of the devolved parliaments since people in England won't generally be as interested. I wouldn't blame people in Scotland for not caring about HS2 much, for example, whereas before the monstrosity was scrapped, a lot of lovely, biodiverse green places fairly close to us were going to be obliterated, and it was infuriating that the concentration was on getting commuters from A to B faster, as opposed to our parks and nature reserves being destroyed, while our MP sang its praises. However I accept that someone in Milngavie or Kilmacolm, for example, probably couldn't get too worked up about it.