You can change the category (or anything else about your listing) until you have a bid, so you still have time. I'd change it if I were you, might get more bids!
That's a good idea. What I do is try to list a few similar things at one time, and put them in different categories so people searching will see at least one of them. In the listing I say "please see the other *** I have listed this week!" So hopefully they'll look for them even if they are in different categories.
I have some old necklaces listed this week that I'm thinking beaders might want to take apart, so I listed some of them in jewelry and some in Arts & Crafts beading category, and said in my listing that I have more of them.