Don’t have any ideas for the brushing, as my bun also hated brushing and will hate for days afterwards. I’d say the most trusted list of suitable vegetables is on the House Rabbit Society site. I’ll put a link here below. Beware though, some vegetables need to be fed more in moderation than others because of oxalic acid (gasiness) etc. It’s all very well explained on the HRS site. It also depends on the rabbit, you offer a very small amount of the vegetable you want to feed at first, you watch the poop and their behaviour. If all is well, you give a bit more the next day, and the next day and so on. If you offer a bit and they stop pooping for example, dont feed anymore, try another vegetable. You would need to do that for every vegetable too, it’s all a bit of a pain, but they have sensitive stomachs and they would get a massive shock if you just fed them a large amount of kale unexpectedly.
://rabbit.org/suggested-vegetables-and-fruits-for-a-rabbit-diet/

Is he a food crazy bunny like most bunnies are? If he is, you can sneakily brush him when he’s busy eating. Food is a great distraction :p I groom Kurotta when he’s eating or lounging because those are the only times he would stay still enough.

Boo has provided the link from the HRS, but off the top of my head a list of safe veggies include romaine lettuce, coriander, carrot tops (not the carrot itself though), basil and bok choy.