The only thing that seems worrying to me is the hair. Hair can cause blockages or wrap around the intestines, both of which are dangerous. You might have to vacuum more often to avoid him form eating stray hairs. Brushing him can help him from eating his own stray fur as well

Is his stomach bloated at all?

Bunnies will ingest some hair when they groom themselves. It’s nowadays not believed to be the cause of GI stasis. You often see poop like beads on a string when a bunny is shedding. You should still brush and/or pull off loose fur from your bun when he’s shedding, preferably daily.

The undigested hay could perhaps mean his tummy isn’t processing the hay fully. If it’s a new type of hay for him, maybe his tummy just hasn’t adapted to it yet?

If he eats, poops, looks happy and likes to groom you, it sounds like he’s perfectly fine and happy =)

Orchard grass is softer so might be easier to digest. But if he loves the timothy, you could try pulling it apart or cutting it into smaller strands for a week or two just to get him back on track. If he isn’t chewing it well enough, it may be a tooth problem. Clearly he isn’t in discomfort since he,s so happy.

You could perhaps try a hay-ball of this type (there are many many types) https://carousell.com/p/15479331/ or a metal-grid hay rack, sth that he has to pull the hay from and work a bit to get the hay out of. You do it with horses to slow their eating down as a form of enrichment – the animal has to work a bit for its food which is a more natural way to get food, actually. With a greedy hay-eater, this is an excellent way to give him a meaningful task + slow down his eating. With a lazy, picky hay-eater you’d not do it because that bun wouldn’t bother.

Most important of all though is that if he wolves down his pellets, almost inhaling them, don’t serve them in a bowl but scatter them or serve them in a treat-ball that your bun must roll to get the pellets out of. We have had a few cases here where greedy buns actually have breathed their pellets into their lungs, and the outcomes have been tragic. This is just a friendly warning, in case he is that type of bun.

It’s really great that he loves his hay btw. Hay is the foundation of good bunny health!

A treat ball can be fun and provide exercise, but a young bun generally binkies around anyway, so the exercise part is more for older, lazy buns like my Bam who needs food as an incentive to run around.

You could perhaps put smaller wads of hay in different places so he has to go from one spot to another to eat. You can stuff hay into empty toilet rolls. Don’t make it super-difficult for him to get to his hay, just a little bit.