do I need to do anything to a branch I'm planning on putting in the coop?

I used oak branches that came down in an ice storm a few years ago. Some people recommend taking the bark off but I never did. Roost mites can live in the cracks and crevices so the bark gives thema great place to hide during the day. I've never had a problem with roost mites so I haven't bothered taking the bark off.

Whether the bark is on or off will not affect how well the chickens can grip or won't affect their comfort.

This shows how I attached mine. I drilled a hole in the end and the support and dropped a big nail in it. This way it is stable yet pretty easy to remove if I need to get it out of the way.

 

I'm not an expert, but.... I can't imagine that you would. I've put branches from two or three different trees in my girls' run for use as roosts and never had any problems at all. The only problem I can imagine is if the branch sat in a infested place on the ground for a prolonged period and became infected there. Otherwise my instincts say no problem. However... I wouldn't bet the farm on my instincts alone.
I'd be curious to learn too if anybody else has any knowledgable insight.