Re: UK Tax question
If you're still worried the best thing to do would be to phone the inland revenue help line. They'll tell you what's what. Or even ask an accountant. It's possible that you can argue that you're still in the market research stage of a business: ie. Youre trying out to see if it would be viable to become self employed in the art business.
And you're probably mistaken about making profit as when you add all of your start up costs etc up, it'll come to quite a substantial amount. Therefore = a net loss. My first accountant that I had when I left art school, made me write an itinerary and I had already acquired a significant amount of art materials, cameras, computer, tools, easels, bicycle (used for transport), objects, books, frames etc.
Whatever you do, KEEP your receipts from now own, whether you inform the IR or not. I hardly had any to start with, but I believe my accountant knew that there were acceptable costs involved in maintaining a studio and was able to put a figure down based on my itinerary. The IR doesn't waste money chasing ghosts (I think?).