Welcome TinyPaws !

My first rabbit was an “acquire first, research after” scenario. I hope your journey is as rewarding as mine has been.

At 10 weeks, it would not be unusual to see some excess cecatrophs. Tweaking the diet a bit is always a good starting point.
I would nix the banana treat as that could be a culprit. Try avoid sugary type treats when they are this young. As a treat, you could offer some dried willow leaves, apple or pear leaves. Although it doesn’t sound like much of a treat to us, rabbits really love them.
It’s often recommended that young rabbits are on both alfalfa based pellets and alfalfa hay. However, that can be too rich for some. So the combo of either; adult pellets + alfalfa hay (like you have done) or Alfalfa pellets and grassy hay can work better for some rabbits.

If you start to see an increase in the soft poops and not change after some diet modifications, I suggest getting him check for coccidia infection. At this point, it doesn’t sound too bad if only producing a couple messy poops. Fingers crossed!

Also, I know he is young but am wondering some things about litter box training. He has a litter box in his cage with access to hay in it but he NEVER uses the litter box. He poops and pees all over the cage and uses the litter box as a bed. I have tried adding a bed for him, giving fleece, leaving the bottom of the crate bare but regardless he goes on everything but the litter box. He does not seem to be worried about marking though. As of now he NEVER poops outside of the cage when he is allowed out and has only peed once. I am just wondering if there is something else I should be doing to get him to go in the box or do young buns just not get the concept?

What size is the litter box? Perhaps a bigger one is worth a go. Or adding a bigger one in along with what he has.
Do you put hay in the box or in a hay rack above the box? A good way to get them pooping more consistently in the box is putting the hay there.

It may be just his age. When rabbits reach “puberty” especially, they can regress in litter habits. Sometimes it’s not until they are desexed that you’d start to see positive changes.

Lastly, is there an age where you pretty much know their personality type? He is super sweet, chill, has never bitten me, not very affectionate though but I am perfectly okay with that. Just wondering if this is the personality I can expect of him or do their personalities change after a certain age?

I *think* people generally say when they reach adulthood you get an idea of their true personality. Baby rabbits can be very sweet and quite trusting. Pubescent rabbits can be really annoying! My own experience with male rabbits is the baby vs adult personality is pretty similar but they are just toned down more in adulthood. The passage of time also comes into play with their level of trust in you & just the bond between you developing.