Painting unfinished attic, what are the pros/cons?
Cleaning up

Pro: Reduce fire risk from scrap kindling material.

Pro: reduce wildlife habitat internal to house.

Con: It's work. Not that much of a con.



Painting

Pro: easier to see (if you paint it white.) 

Con - expense (money and time) .vs. amount of time you'll spend in it, since it does not appear to resemble living space or enough space to convert to living space, unless you are housing hobbits or leprechauns.

There is no real benefit to "sealing the wood" since there should never be weather in here. Kept dry, "unsealed" wood lasts for hundreds of years.