Hello phtimo,
We definitely want to make sure that your phone is functioning properly and as it should and that you are receiving only the notifications you really want. For the power saving icon: Turn off power saving mode by going to settings and then go to "power saving" and there are 2 options there: Power Saving Mode and Ultra Power Saving Mode. You can turn them on and off from there. Once the power saving mode is off, the icon should go away.
Please let us know if you had any additional questions.
Thank you!
Alissa