I never realised 'wean' came from wee'un. Makes perfect sense.
'On' (or 'of') 'a' morning (as opposed to 'in the morning') are regional. The brought/bought thing is perhaps not regional as such, but I think more than a simple error - I've known very educated people do it.
Ibuprofen (alongside the brufen confusion - I've known doctors call it that) is hard to say as it's written. A bit like February. There's a tendency to insert an extra 'r' into the former ('ibruprofen') and leave the first 'r' out of the latter ('Febuary' - which I am guilty of, but believe (I would, of course) it's a legitimate variant of the pronunciation).
I'm a big yous/youse fan. Don't use it as it doesn't occur in my variant of English, but I love the capacity for differentiation it gives (and I deplore the snobbery that has decided to label it uneducated or 'wrong').