What it's really important is the headroom between the peak level and the average level (LUFS, RMS), so instead of expecting night and day results from the mastering process, it would be better to invest in a very meticulous mixing session. I also avoid using effects on the master bus (Top down mixing) if the mastering will be done in another studio.

 

You can try lowering with a VCA fader, it wont always work, but many times you can fix if the levels are too hot.

 

Boy, you never wrote a sketch and you worry about -1 db at mastering? and copyrights and cover graphics? are you insane lol. Moreover, there is the math of adding peaks on top of each other You will hit the big wall ahead of you so hard . Also , you take mastering advice from..here? lol me again.