How large is your image (file size/resolution wise)? If it is indeed to large for it to be inserted into CC3+, I would probably reduce the resolution a bit rather than cut it up into parts. No need to overdo the quality since it is just for tracing.

You can keep a copy of the higher quality image on a different screen if you need to check a specific detail

I like to use the Color Key effect to punch hole in walls, and combine that with scattering some rocks around. Similar to what I talked about in the ruined walls for perspectives blog, but with much simpler, since it is only in 2D.

Then follow Maidhc O Casains advice about exploding them. This gives you access to the text so you can edit it.

Unfortunately, this doesn't seem to be available any more. Maybe ProFantasy support has an old copy around they may be willing to send you if you ask them.

Looking forward to see these great cliffs in action.