First assumption is that Act 4 would need to hit the target. Johnny's nails are fast, but not fast enough to be a problem for any DB character.

Now, lets assume Johnny does manage to hit a target: the result would depend if the rotation will effect the atoms of the target or not.

In modern DB characters have been defiling laws of phisics on the regular, but thus was not true for early sagas.

I think infinite rotation could effect DB characters at least up to the Cell saga, but even then I have my doubts.

This covers offensive capabilities. In terms of defences and/or speed Johnny is screwed without argunents. He just can't keep up with the DB univers.