Hi Josephine
There are no rules, and remember this is just a forum, with mainly amateurs posting opinions, not facts.
I said on a post in PW a month or 2 ago, that I read and digest what is said on here (and there) and I post occasionally if I feel I can help someone. I used to get quite wound up about other peoples opinions, but now I simply post my view and unless someone contradicts me with something that is clearly wrong (i.e. that's the note B, when it's obviously a G) I don't bother to argue with people. If they have a different view, fine, they may be right, they may be talking codswallop (love that expression), or they may be being deliberately provocative. I'll let them carry on... So my advice to you is to read the posts on here, take on-board stuff that you think helps you, and the rest... well a pinch of salt!
The only person I really take advice from is my Piano Teacher. I'm never going to be a professional Pianist, but as an amateur I've done about 200 non-classical gigs, and I've never had anyone complain about my playing. The fact that my hand position, or my seating position, or my sight-reading, or indeed any other aspect of my ability to play music isn't technically correct doesn't concern me. As you said most of us are in it to have fun. And I've had a lot!
As it happens I basically agree with Pianoloverus, and I'm sure he means well, but if you think some, or a lot of memorisation is the way forward for you, and it enhances your enjoyment of the music then do it. Take no notice of what anyone says on here and have fun!
Cheers