I don't know why the bottom isn't being rendered. Normally you put a 'drip bead ' right the way along and render above and below!?! Regards the piece of wood, I disagree that it will look wrong painted in the same colour as the render, the only alternative that i can think of would be a ' plank ', of upvc, but that would be white and stand out further.

No doubt you have tried this but just in case.... have you tried googling the oven make and model (if you know it) to either look for an online copy of the manual for manufacturer instructions or to find videos of other people removing and cleaning the door? Had a similar ish issue myself recently and google saved the day!

I think we're touching a very broad subject here. Art can be many things. Not necessarily paintings what you put on the wall. For example I like anything floral and botanical and appreciate the work that's gone into making or growing something, wether it's a beautiful climbing rose, a wood carving, hand painted water colour or a hand embroidered cushion. My hubby in the other hand likes the inner workings of engines, computers and anything mechanical, to him this is art. So you can imagine the eclectic mix of stuff we have in our house:) Good place to start is have a browse at sites that sell prints like Art.co.uk or Allposters, there are thousands of images but you might be able to narrow it down to things you like/dislike. Alternatively shop around, if you see something you love then take a photo or better still get it! If you have a local art college you could also take a visit there. I'm sure lots of students would be happy to sell their pieces, you'd get something original at the fraction of the price of an art gallery plus you may even be able to commission someone for something unique for yourself. I might be a bit biased as I went to art college myself and could rant on for ages on this subject but I've hoped to have helped a little.

Whilst there can be occasions when it may be more hassle/work to re-fit existing kitchen units into a completely new layout, this doesn't look to be the case with what you want to achieve. Your kitchen looks in good condition and you want to have a single run of units on the wall opposite your new sliding doors. As a carpenter & joiner I'm struggling to see any difficulty with such on the basis of the info you've provided. At worst you may need a new worktop or section of such and/or end panels. If you've got a full wall of units the opposite side you could potentially use some of those to form your new island (depending on what sort of configuration you have in mind), with the addition of new doors, heavier end panels & stone worktop to contrast. There shouldn't be any problem with re-using your range either (just check sizes), and £100 or so spent getting an oven cleaner in should have it looking great with your new layout, until you decide to replace it.