I agree with you. I don't look too deeply into things either, and I don't look for theories in things such as the much debated 'was Enid trying to make some kind of statement about feminism, lesbians, women, genders, etc' with George - I just think she was writing about a girl who liked pretending to be a boy, no issues, no hidden meanings.
I just enjoy all the books for what they are.
I never bother about anything that seems 'contrived' or convenient, or an amazing coincidence, or things that don't add up, or plot holes, I just love reading them so much that nothing bothers me.
There's debate about how convenient it was that Prince Paul was given an aeroplane in Secret Mountain, just when they needed a plane, but that has never bothered me at all and I don't think I even thought anything of it until I read the discussion here (I first read the book at about age 8, so that's almost 30 years of not being bothered!). Who cares, its a fantastic adventure.
The only reason I rate Rockingdown a bit lower than the others is Diana and Roger seeming a bit mean and spoilt at the start, because we know from the rest of the series that they're not actually like that at all.
I love the creepy old house and the mysterious happenings, I like Mr King (hence the surname of my username!) and I like the plotline.
I think my order would be
Rilloby Fair
Rubadub
Ragamuffin
Ring O Bells
Rat A Tat
Rockingdown
but I could easily interchange Ring O Bells and Rat A Tat, and possibly sometimes Rilloby and Rubadub too, my favourites change all the time depending on which one I'm reading.