Hi Starman
Things to consider. Type of wood; the harder it is the less impervious to damage. It is more expensive though. Having said this a good wooden floor is an investment.A kitchen is a high traffic area so this would be a major thought. No matter what type of wood you use the finish is very important. We use Sadolin acid base varnish. It is extremely durable and takes heavy traffic with ease. However being an acid base the premises must be vacated during application and a good chemical mask must be worn. Some people think that a good varnish over a soft wood, eg. red deal will do the trick. Not so as a good quality varnish needs a hard substrate to be able to do its job efficiently. One can thin down the first coat of varnish so that it permeates the wood structure deeper as a normal application would. Followed by normal applications.
As regards damage modern day appliances are reliable and should not pose a risk if properly installed and maintained. A correctly installed and plumbed sink should not give any problems either. I agree that wooden floors can suffer huge damage. But in the most part due to leaks that have been unobserved for long periods of time.Bad plumbing, incorrectly installed splashbacks etc.
I presume you will use a reputable installer. One that would leave the wood in the premises to acclimatise its moisture content, unless of course it is kiln dried. This will ensure its stability once finally installed. There should be no fear of the gaps you mention.
Having a continuous floor in an open plan increases the sense of space, this is after all the whole point of open plan. Let's face it wood is beautiful, warm, and lends a good ambiance. Being realistic its a fact that as opposed to tile more care must be taked with wood floors. But it is worth it in my view.
