I don't really believe the "don't ever raid with your SO/friends" because everyone is different. I raid with my boyfriend and our friends. We know the difference between the raid/fc leaders talking and the boy/girlfriend and friend talking. In the past when I have had to confront a member about an issue I simply said to them "right I'm going to put my fc leader hat on now and talk to you about something that needs to change". If I need to get serious, I make it clear that it's me as a leader upholding my responsibility not me trying to shake up our personal relationship. If they see it as the same thing, then frankly they're not mature enough to raid.

A lot of what I learned about leading is from watching others in the past doing it wrong. I stayed in some guilds for years so I could see the long term effects of bad leadership. The most common mistake was not being consistent with rules. It was obvious some were allowed to bend and break them more than others, and often months would pass before it got dealt with, if it ever did. Too much tolerance is another common thing. It simply doesn't work to wait until a problem is huge before dealing with it. Doing that just lands you with a horrendous and maybe even impossible mess to tidy. I can't even begin to count how many times I have watched too much tolerance result in several people leaving. One of the most important things I have learned is that you can't please everyone, and if you try to most times you end up pleasing no one at all.

My static hasn't had the epidemic of problems OP has, but we did have a member of the raid team who was often late. We eventually had to kick them from the team, but we made it clear that our issue with them was purely related to raiding, so they were allowed to remain in the fc. Aside from their tardiness they were an otherwise pleasant person.