Surely a month-old vacuum cleaner will be under warranty? You didn't misuse it so even if it had (miraculously) stopped working after you used it it's not your fault. I'm assuming that, like most us, you have plenty of experience of vacuums at home, it's hardly like you were using a new and rare piece of specialist equipment
).
The loo rolls, kitchen roll and cleaning products are there to be used - you shouldn't have to replace them (not when you're paying £600 per week). Likewise, breakages should be seen as part of holiday lets. I'm not advocating that it's ok to stay somewhere and carelessly fling the glassware around but I do think that leaving an expensive vase around is pretty stupid. If the vase was so valuable I should have expected her to point it out to you so that you could put it away if you wanted to. Was the rest of the place filled with priceless antiques?
I agree with everyone else that she's trying it on and, btw, I think it's pretty nasty of her to do so, especially when you'd been kind enough to leave the place so clean, leave chocs, etc..
Let the insurance company handle the vase issue (perhaps express your reservations to them), tell her to get the vacuum fixed under warranty and ask her to demonstrate why she is seeing this as your responsibility. I would also contact the letting agent and let them know about how she's treating you (a dishcloth FFS!). You could say that you would have let the lack of cleanliness and other shortcomings go but, given her conduct since you left, you feel pretty peeved and want to express that to them.