the older woman has her house abused and is treated like a maidservant instead of a landlord.

... by Sherlock, who's kind of an asshole and treats EVERYONE like they're his servant. Yes, even John. Hell, ESPECIALLY John.
[Sherlock's phone beeps]
"Pass me my phone."
"Where is it?"
"Jacket."
[John looks around to see that Sherlock is wearing his jacket]

Oh, and the shooting the walls thing is canon; the original, Victorian Sherlock did that, too.