I'm now learning about Artifacts since I finished all the Summon Trials in World of Illusions. So basically, I just farm the two Artifact options and I can only do a couple of battles or whatever unless I plan to use Stamina Potions, and thus I hope to get a 4*, and in fact a 4* that I need/want? I'm not 'outraged' at the potential that could mean for long-term grinding, but I just wanted to make sure I understand correctly.
Seek the XX: 2nd tier, the end boss level for each "branch" of the map, drops a combo of 3* and 4* artifacts, but it's not exactly where you wanna dump your stamina. Every time you clear it, there's a chance it opens up a bonus level. That one always drops 4* and..is much easier to boot! So, yeah, what you can get can be pretty random still. It's what makes the current map great for farming...much higher chance of getting the artifact you do want over the regular WOI artifact map.
The co-op event(s) also have artifacts as drops and and for token exchange.
Also, I guess once you reach around 50 crystal level, the daily cycle quests don't always net you much. For example today was white crystals and it only took my Eiko from Str 48 to Str 49. For said crystals, I have 597-261-85-5 -- I guess there isn't anyway to "orb exchange" like FFRK has is there?
Yeah, not yet. You could burn a key and run it over and over again until you get what you want if you wanna rush things a bit. Also co-op as drops/token exchange.