Regional accents, pronunciations etc are what they are. If you live in the SE, your LOs will pick up that accent, likewise if you live in Scotland, Ireland, Wales, or anywhere where the local dialect differs in pronunciation, that's the accent that will be acquired, by anyone learning the language.
DH is not originally from Britain, and from his early years here, and who he was living winth, has picked up an Irish influenced accent. Many friends of his were married to SCottish women, and they have their own scottich influenced way of speaking.
Nothing wrong with that.
Dropping the 'h', the 'th' or the 't's are MIS-pronunciations.
My DS has just learned how to say the TH, it was a struggle, but he always knew it ought to be said like that, only his tongue was not developed enough to quite grasp it... Until yesterday actually!
He said Be'er instead of Better the other day, and I asked him where he'd heard that. The telly apparently. ()
I gently explained that it's Better, it has 2 T's in it, so best to pronounce them so people can understand what you are saying.
ANYFINK is just plain WRONG.