so my issues are really simple:
1.the crate have no-texture particles when we break them
2. the crystal doesn't seem to spawn? (but idk where they are suppose to spawn)

my suggestion is also easy:

1. making the creative tabs cleaner (in a logic order, like Armor set,after weapons and after crystal types.
2. nerfing the crystal's explosion when we walk on them. i think they should only explode with a really small radius (maybe destroy 5 to 8 block, not really more) so they don't do gigantic hole for nothin

issue - 1 Ill make a note and fix, i forget thats an issue still...
issue - 2 [intended] Crystal Ore is super rare in normal biomes (intended) and reasonably common in the "Crystal" biome between 0-200 except for 2 which are limited to 0-30. The best way to search for this ore is to use spectator mode or with wizardry installed, the "Phase" effect. As the 3d-ish texture makes it super easy to see underground. ALSO ore gen is a config option as well for those who want to make it more common.

suggestion - 1 I agree, Creative tabs are a bit messy, ill make a note to look into this, but hey, JEI/NEI list is decent, which most people use anyway.
suggestion - 2 [intended] Cluster size determines the explosion size, so a cluster with 1 or 2 (cant remember) has the normal tnt explosion size, tier 3-5 scales from there. ALSO there is a config to disable this if you dont like this effect.

Ok thx for those informations!

Fix for Issue#1
As well as Fix for Suggestion#1