Awww...not need to be stressing out
Since he is a boy

and you won't be eating (his) eggs or I don't believe you are planning on eating him. I would be inclined to use Ivermectin for the Scaly Leg Mites. From what I understand feather footed birds are a little harder to treat just because of the feathers. Scales on feather footed birds may also appear
slightly raised due to the feathers, but generally they should be smoother.
You can find good info on dosing and administration here:
Mites/lice - now hen growling?
When you treat the Bumblefoot, you will be soaking the feet/legs anyway, so just give those legs a good washing to soften the scales. You can still apply some oil to bring the scales into condition. It will take time and patience to get his legs, nails and feet corrected. I do think, that once you get them in better shape he will be fine.
There are a lot of different methods for treating Bumblefoot. If it is on both feet, I suggest treating 1 foot at a time. Pick the worst one, treat, get it healed then do the other one. Some people soak in epsom salts, betadine, chlorhexidine then perform "surgery" by cutting the bumble out.
http://www.the-chicken-chick.com/bumblefoot-causes-treatment-warning/ You can also try a less "invasive" method first by using Clear/Decolorized Iodine
Does my chicken have Bumblefoot? This method would probably work for the ones that are on top of the feet.
Help with beak/toenail trimming:
https://countrysidenetwork.com/daily/poultry/feed-health/trimming-chicken-beaks-claws-spurs/
Different methods for treating SLMhttp://
www.the-chicken-chick.com/scaly-leg-mites-in-chickens/
Hope that helps