Well then, 5% per point of energy, needing 420 tickets for 7* unlock means 420 * 20 = 8400 energy.
daily energy = 375 free/accrued + refreshes.
No refreshes = 22.4 days.
But the drop rate might be closer to 5.555%, & if so then the time to unlock is 8/9ths of what we just predicted. So we actually get
19.91 days (optimistic) to 22.4 (pessimistic)
1x50 energy refresh per day = 495 energy per day =
15.08 to 17 days
2x50 energy refresh per day =
12.14 to 13.66 days
3x50 energy refreshes per day =
10.16 to 11.43 days
If you're not going to have all the g1-g12 gear ready for 12 days, you might as well do only 2 refreshes per day. If you're not going to have the gear gathered for 10 days, you shouldn't be doing any 100 energy refreshes.
The rest you can figure out.