So something i just really dont like is kits that dont scale with a certain stat. Abilities that always crit translate to kits that dont scale as well with crit.
Destruction warlocks bypass this by having their total damage scale with crit, which works, elemental shamans however only get this while in ascendance.
Now, copy and pasting warlocks system could work out fine, and im sure that i have seen this suggested multiple times, but an alternative idea i had was making lava surges proc chance be based on flame shocks crits, that way there is still some late Xpac scaling.
This alternative scaling would alter the gameplay somewhat and could have some interesting interactions with talents.
Just an idea anyway, i still believe that lava burst needs crit scaling in some way, this solution limits burst (in case PvP is the issue) while affecting mobility (more instant casts)