I like the orange paint. It is pretty hard to maintain any non-catalyzed paint on a bike. Most petroleum products tend to dissolve most petroleum products. Spray can engine paint baked in your oven lasts a lot better but is not immune. 2K urethane clear is available in spray cans but like all 2k, you have to use the whole can straight away once you combine the 2 parts. Lots of folks here have used this over regular paint with great results but there can be difficulties depending what the base paint is. Poke around in the paint section and you should find some good info.
If you have any concerns with the front tire clearance, I suggest you change to a smaller tire. I can almost guarantee your bike will drive noticeably better. I'm a big fan of the Avons, but too large a section - especially in the front - really degrades the weight and feel of the handling in most cases - every case in my own experience. It is a common notion these days that larger tires will be an upgrade on old bikes because new bikes have tires that in the main are so much larger. We are used to seeing them and the stock size tires on old bikes tend to look really small by comparison. Doesn't mean they don't work well - I have had guys on new sport bikes come up to with comments like "man, I thought for sure you would crash on those skinny tires - I was working to stay with you!". Most of the time I ride a stock (looking) RD350 Yamaha, and though the tires are 1 size larger on both ends, the back tire does indeed look very skinny. Any bigger on the back still it drives ok but feels slower, and any bigger tire on the front is a disaster. I have a CB400F that behaves much the same way, but probably even worse with too big a tire on the front.