How to decrease Print Start Time  

RE:

For the absorb heat phase you can either press "skip" on the UI screen or disable for certain filament types in gcode. To do the later you can add the following to the Printers->Custom G-code section or you can simply remove (or comment out) the G29 G ; absorb heat line. 

{if filament_type[initial_tool] !~ /.*(FLEX|PLA|PETG).*/}
G29 G ; absorb heat
{endif}

As for (temporarily) skipping the bed leveling and reusing the previous mesh. You can comment out this section:

;
; MBL
;
M84 E ; turn off E motor
;G29 P1 ; invalidate mbl & probe print area
;G29 P1 X150 Y0 W100 H20 C ; probe near purge place
;G29 P3.2 ; interpolate mbl probes
;G29 P3.13 ; extrapolate mbl outside probe area
;G29 A ; activate mbl

Also, for example, perhaps save the profile as "Prusa CORE One 0.4 nozzle (skip bed level)" I wouldn't skip bed leveling all the time. If you are doing a print, remove the previous print then do another then it's probably safe to skip. I usually don't bother with this unless it's a really small print. 

RE:

What I'd do is go through the profile's G-code and remove the problematic codes. M109 and G29 G come to mind (for me it's OK to calibrate at uncontrolled nozzle temperature but of course you need it once for printing)

edit 1 min late - see above.