Sorry OP but your posts are full of resentment towards your LL and you are equally making sweeping statement s about landlords.
Why? How do you know what goes on behind the scenes and what her finances are? I would imagine communication could be problem here.
We rent our old house. It used to be our home. We are reasonable people, as are our tenants. This is based on mutual respect not a them-and-us scenario.
We have been asked by our tenants over the years if they can decorate, put pictures up, add plants to the garden, have a cat and even just recently our current tenant has asked to install a water-butt.
This is all agreeable as long as it's returned as it was when they moved in and carpets/curtains professionally cleaned in the case of cat requests incase the following tenant has allergies.
In return we fix any problems quickly, are respectful of their privacy, specifically ask if it's ok to give the plumber a key etc. We also, like other poster's here, charge below the market rent in order to keep good tenants.
This respect works both ways and communication is key. Perhaps we have been lucky but we've never had to deduct a deposit.
Perhaps ask for the things you want with an assurance that you'll leave it in it's original condition and you may be surprised at the answer.