Would I be able to swap my engine and all my running gear (suspension forks wheels gas tank etc) from a 2007 Honda crf70 onto a 1999 xr70?

It's a 99-97 frame for xr70 I have I wanna know if they are compatible

I had a look at some photos and the design has hardly changed in 8 years, mainly cosmetic. I would say that yes, it should all swap over but there may be some issues if they have changed some sizes, like steering head, swingarm etc bearings, but would be unlikely.

I doubt it very seriously. Look at the motor mounts very closely. And all of the other mounts. (fuel tank, fenders etc.)