You get 3-4 crystals from dailies. Not exactly time-efficient, hence my question for an alternative. If by exploration you mean gathering, I have yet to see a single crystal drop from that. I did have a Flower Gem drop, once. And no, not talking about dailies here (go on 4 gathers, 5 gathers), but exploration itself. Same goes for event. You only get them in fancy chests, not by 3 medaling a stage (that's Flower Gems, again).

I am on the part of the game where ampys are low priority and will only be of any use in 4 months from here. Same drill for 6* and 5* skill blooms (I have no 6*s, so it's pointless). Manyus on the other hand are something needed in this moment, in other not to burn so much gold in upgrading, saving it for evolutions instead, and equipment upgrade. So, sticking to Advanced 1 will be the thing for now, until Ultimate 2 is up.