There's been nothing announced on the show that clearly says that a team with an Express Pass can't use it on a Fast Forward. So it is possible, but it's not clear that in all instances it would be wise to do so. If you are going to win the FF anyhow (as in only team to go for it) then you might as well hold on to the Express Pass for another time, unless there's some unusual circumstance.
As to the Express Pass being used on a Speed Bump -- wny would a team not have used the Express Pass on the prior leg to avoid being the last team to check in on the NEL? Assuming that a team did find itself in that situation, again, there been nothing I've heard announced on the show that would preclude this from happening, but it's hard to imagine a circumstance where a team would still have an Express Pass when they have to perform a Speed Bump. But from what I've heard in its current formulation, there's noting preventing a team from using their Express Pass on a Speed Bum.
Now there may be a detail teams are told that we haven't heard on the show, but that's something I can't answer to -- just what has been shown on air.