Hi @Arlete4 this doesn't sound good - how much longer are they staying for? Some people simply have no common sense or courtesy. You are well within your rights to ask them to have shorter showers and to not wash their dishes under running water. I state on my profile and in my guest booklet that showers are to be no more than 5 minutes long, plus I have water-wise stickers everywhere and a timer in the shower (we do have water shortages and water is very expensive here). People breach this all the time, but at least it plants the seed so that they hopefully don't stay in there too long.
I have also had issues with kitchen use in the past - I used to allow use of the kitchen for quick meals and light meal preparation. However, after months of putting up with exactly what you have described, people taking over the kitchen for the entire evening so I can't even get in there myself (not to mention using all my oils and condiments, burning my pots, leaving burn marks on my wooden bench tops, etc. etc.). Unfortunately, because of these people, I have now stopped the use of the stove and oven altogether - guests can still use the kettle, toaster and microwave. Interestingly, I now get a completely different type of guest (i.e. ones that are happy to go out for dinner!).
Regarding your current guests, remember that they are staying in your home and you need to clearly state your boundaries. Explain that you are unable to get into the kitchen to cook your own dinner and ask them to cook simpler meals. Ask them to have shorter showers and to fill the sink to wash dishes. Probably not a lot you can do about the arguing.
Above all, DO NOT LEAVE THEM A GOOD REVIEW. We hosts need to look out for each other because Airbnb doesn't - we are all we have.