For the records, there are people who actually filled the wish bar, that is to say things like 30/30.

No, full wish bar is not auto upgrade, full wish bar is guarantee next one to be successful.

You need enough lv 3 charms so that you do not have a lv 6 or higher rainbow magatama, as there is serious diminishing returns for high lv magatama. Beyond that, even level up is fine.

If you complete all the ultimate training, you should be able to get most things to 3.