Nice strategy! I love the idea of the daily quests but still couldn't complete them. Something similar to your step 1 had briefly crossed my mind but I can't apply it at the moment. My main team brought me to Bronze I with around 700 points and is facing opponents with around Common card levels 2-3, and my earth cards (the splinter I got assigned for the daily quests) aren't up to par for my current league. If only the daily quests had come sooner...

I'll try to apply the strategy once the new season starts and we have more time to drop to the bottom ranks and then climb back up. It'll also be interesting to see what happens once the recently announced level cap adjustments kick in, which will adjust the levels of everyone's cards according to the maximum allowed for each league, so that we don't run into way stronger opponents as long as we're in the appropriate league for our cards' levels.