If it smells like pets, you’re probably going to have to take out the carpets and underlay and replace with your choice of flooring, so I would work out the cost of that first. As a guide, we recently re-carpeted 2 bedrooms, £800 for the big room, £400 for the smaller. Nothing, trust me, nothing, no matter what people recommend, gets rid of the smell of pet wee out of carpets, on a warm day.
I agree, that plastic beam stuff looks retro-fitted, so should come off without causing any major damage to the walls and ceilings. My H would do that himself, but he’s handy. You, or your tradesperson, will need to do some filling and sanding, possibly replastering, once it’s off. You could ask your surveyor to check it’s decorative rather than structural.
Once you’ve done those two things, I think there’s a good chance you’d have enough left in your budget for a moderately priced new kitchen, but the kitchen is functional and not awful, so you could wait and save, and put in a really nice one when you can afford it.