New player 200 hours

Hi all, I’ve just started gaming again after a 20 year hiatus.

I’m loving Skyrim and I’ve gotten good at it, I’m a Redguard playing Dragonborn quest and I really love it but starting to get bored around level 47 which I’ve heard is common.

I have been making up my own rules so have probably broken some cardinal sins and am still finding out new things all the time.

I’ve been leveling up skills wily nilly so not sure if that’s bad.

Magic was so hard for me when I first started but now I get it more but feel like I still don’t really get it.

My main question is, is there a common thing I’m missing or any critical quests I should do. I need to level up more to do anymore Dragonborn quests.

Also I think I accidentally joined the Imperials, is this bad. Should I just start a new game?

Also I own three houses and have two kids and a wife. Is it bad to own multiple houses? Like am I considered a traitor?

Thanks in advance.