Stray rooster found me, any care advice?

This pretty guy started showing up 3 days ago and I was finally able to catch him. Despite acting like I was the antichrist previously, he has been super chill post capture.

He is separated from my flock for standard quarantine and due to congested breathing. Im treating with VetRX.

Questions:

1. When should you start to see improvement if VetRX is helping with a respiratory issue. When would more intense medical intervention be needed?

   1. Does it look like he has mites? His legs are certainly on the dusty side and I want to be safe so I dont spread anything.

There's been no luck locating his original home so he either escaped and found my flock or was dumped. He's gorgeous - came with nearly every add on installed (5 toes, feathered feet, walnut comb, muffs, cool hat). He was also a gentleman in the short time he was around my ladies, so if no owner shows, im probably keeping him.