To be bracing myself for landlord to try and take all our £1,200 deposit back

[Helpmepleasenow48]

We are now the proud FTB/owners of our first home. We were previously renting for 10 years and moved to our new home 2 weeks ago
Now the property we were renting was in a state needing decoration when we moved in. Things went wrong as soon as moved in - only minor things like drawers coming out and hinges going and a mirror frame fell apart when we moved it. The upstairs toilet seat broke but it was an an unusual shape so the landlord had to order a new one and even when it was replaced the hinges weren't and ended up going rusty. The garden bricks started falling apart from frost.
Then the bathroom floor got a hole and the oven stopped working and the boiler made s terrible noise.
We reported all these things to the landlord but only the oven was fixed. Over the years she put the rent up from £750 to £995. She never visited and even left her agreement with the rental agency so they all but collected the rent. Anyway about four years ago we knew we were going to come into some money and we communicated with the landlord that we might buy the property. Basically we had it valued but she wanted more than the value, we also had building work and damp proof costed - which would have cost at least £30k.
So we put in an offer on a property nearby in November and now own it. We did our best to clean the property - we gave her a month's notice, but we think she's peed off because we didn't give her more notice/offer her more for the property. When we told her the bathroom floor was broken she told us she expected us to mend it. She said she was renting and made minor improvemts to her home. We know she's on an interest only mortgage because all her mortgage statements were sent to the address. She paid £500 a month and her mortgage is actually more than our new one! She owes £220k and we have £200k mortgage. This I digress a bit but we are pretty sure this income hasn't been declared to HMRC as I set up a limited company and rang them last week to change address they wanted to know who owned the property. I told them we rented through a letting agent.
So now worried I may have dobbed landlord in and we won't get our deposit back.

Ok. Now she's screwed you for money you didn't owe write to the mortgage company and HMRC and let them know she's letting the property.

You've paid her money when you had zero obligation to.

No idea why you kept conceding money. You just gave her £260 for no reason and reconfirmed to her that being a lying, greedy arse is productive. So what if she's a mortgage prisoner?

But I guess if you're happy with it, that's up to you.

I have to say that once the LL didn't repair things for which she was responsible, I would've been returning-to-sender any letter that was addressed to her. You were her tenants not her secretary!

Though opening her post isn't great, it could be in fact of interest to the tenant if the landlord hasn't got a BTL mortgage given the potential implications of repossession.

You did back down very easily, but otoh sometimes a lower amount of money now is more important than getting a bit more in the future.