Brand new MBP '13 (2019) taking 45+ seconds to start up

[Lyrca]

If it isn't at least 2.6 GHz I'm out

What are you computing needs that you need 2.6Ghz and more ? Also as mentioned earlier clock speed does not tell the whole story.

 

[Honza1]

Also as my MBP seem to lose these days anywhere from 0,5% to little over 2% overnight just powered off, I think drain in sleep mode would be much more, so this way I have more predictable battery left when I use it next time.

That's bit unusual. My MBP looses less than 2% overnight (well, depends how long the night is) while sleeping. Now, every battery will loose few % from 100% when not in use - and 0.5-2% is probably at or below battery sensors ability to measure anyway. But have you left computer powered off for longer time, is it loosing power further? I would not expect it to loose much beyond few % and then level off - when powered off.
Power draw while sleeping depends on which device you have (higher end MBP needs more power - larger RAM to keep powered), but I never lost more than 5% in 24 hours while sleeping and that is negligible value in my use.

 

[0906742]

That's bit unusual. My MBP looses less than 2% overnight (well, depends how long the night is) while sleeping. Now, every battery will loose few % from 100% when not in use - and 0.5-2% is probably at or below battery sensors ability to measure anyway. But have you left computer powered off for longer time, is it loosing power further? I would not expect it to loose much beyond few % and then level off - when powered off.
Power draw while sleeping depends on which device you have (higher end MBP needs more power - larger RAM to keep powered), but I never lost more than 5% in 24 hours while sleeping and that is negligible value in my use.

I know that at 100% you may lose a lot by just letting battery stand by, but this happens with mine at every level (like last night it was 48,6% I powered it off and today it was 47% when I powered it up the first time) and not sure what the heck is wrong with my machine battery. It used to be usually well within 0.5% or even less overnight when powered off but since installation the latest Mojave patch released just two weeks ago something may have changed as after that is has been pretty steadily closer to 2% and also battery level reporting has changed quite a bit after that (mine used to drop FCC hugely under high cpu load but does not do that anymore but battery in all seems quite a bit weaker now when looking at operating times on battery). I don't think I have yet ever left my machine unused for two days or more, so I cannot really tell if that is just initial drop and maybe not get multiplied daily.