Is it ok to use on block walls in a basement

yes......but you wold have to seal the block wall ? If your going to build a wall and insulate it & dry wall you would still need to seal the wall, there's a rubber base paint you could use and you might be able to glue the panels to the block wall, but I would stongly advice you to seal the block wall ,build wall's dry wall it , insulate it and you'll enjoy it more, this will keep the dampness out and you would be able to heat the room and it would be cool in the summer, plus it will last for a long time, anything else will have probnlems down the road

as long as the wall is porperly dried in, yes