Good communication from the start helps. So being clear as a seller what you are planning to take with you - and bearing in mind it's all your stuff, you are perfectly entitled to take anything with you that isn't fixed. So no-one has a right to your curtains or even to feel peeved that you aren't offering them for sale. Things like fitted appliances and fireplaces, in my view should be included. If you plan to take them, you should say so very clearly from the outset and also that you will replace them and make good any damage.
So I don't think it is acceptable to take out a fireplace and leave a gaping hole, or remove the Aga in the kitchen and leave a huge gap in the wall.
No one should have to move into a house and face serious work because a seller has ripped out fitted items and not replaced and made good.
Bearing in mind the fact that ripping out fireplaces, range cookers and often fitted applicants causes damage and replacing even with cheaper versions can be expensive, most sellers will opt to leave the items. However, they can choose the alternative but being clear they will do that is important - there should be no surprises late in the day re the sale or on moving in.
I was told with one house that the seller planned to remove their favourite plants from the garden and some light fittings (replaced with simple ones) and most curtains and even poles/tracking. I was fine about the plants and light fittings and curtains. It's not very nice moving in and having to put up curtain tracking that first evening before you can go to bed - so I think basic curtain tracking should be a requisite in bedrooms too.
Most of these things are laid out in solicitors papers of what is included in the sale, plus the points about the requirement to make good and leave light fittings and bulbs in each room. However, some people don't read the stuff or just ignore it. You often only find They haven't been left as required when you move in - and at that point few people want to get into a wrangle via the solicitor, so just feel really pissed off and go out and buy some light fittings at 10pm at night, rather spoiling the first evening in the new property.
Common decency seems to elude some people when they move. They think it's okay to leave the sheds or garage sor lofts full of rubbish they couldn't be bothered to get rid of, to leave bare wires hanging from the walls or gaping holes where fixed items have been ripped off - and swan off to their new home, probably expecting it to be professionally cleaned, a bottle of wine and everything beautiful. It is a pressurised time when you move, but I think you can tell a lot about people by how they leave the houses they are selling.