Im lvl 52 with 11k power,and your acc is not so normal. When you started play? I about 16 days ago and i Did many refiniture lvl 3-4(all with coupons) and some to lvl 5(guild coins). Group skill lvl 18~19 and magatamas near to full lvl 3. Thats not normal for a lvl 73.

This is my suggestion:

Stop upgrade your livel.
First upgrade all your strengthen to max.
Do every day ninja exam and sweep it.
Upgrade all equips to anbu or Kage(kage now is a good idea)
Use stamina to improve ur ninja's star to lvl 5 if you can get it in elite instance
Win all kurama's fight and get coupons. Use your coupons for low refiniture and up all to lvl 4. After use all your coupons for common threads and upgrade your battle armor to lvl 19 and rank 3.

U can upgrade your livel only with daily mission,so you c*e all stamina for cards/equips and other :) I do about 1 livel every day