Is there any reason why a rock or celestial crystal can't have a max amount of attributes apply to them? For instance I have a rock crystal with 2 size, 2 shape, 2 tool efficiency, 1 tool durability but I can't add another attribute onto it like shape or size assuming 8 is the max for this crystal. I tried using shape II and size II crystals to merge with it as well soaking in starlight to increase the size but with no change.

I have another rock crystal with 3 size, 3 shape and 2 tool efficiency.

Are you in 1.15? There's currently a bug in 1.15 where growing size with starlight bypasses the limit.

Yes its 1.15. What is the max limit for Rock and Celestrial Crystals for 1.15?

7 is the maximum for rock crystals. This is intended.

For rock crystals it's 7. For celestial crystals it's 10.