Advice on start and end G-code.

I'm using Repeiter-Host to drive my printer.

I'm using the following start and end G-Codes.

Just wondering if I'm duplicating efforts or is there something that should be added or deleted?

; Default start code
G90 ; Absolute positioning
G28 ; home hot end
G1 F2000 ; set travel speed
G1 Z15 ; move to absoulte height of 15
M106 P1 S125 ; turn on cooling fan for bed MosFet
{IF_BED}M190 S{BED} ; set bed tempature to Repetier default
{IF_EXT0}M104 T0 S{TEMP0} ; set hotend to Repetier default
{IF_EXT0}M109 T0 S{TEMP0} ; set hot end tempature to Repetier set point
; and wait for it to be reached


; Default End G-code
; The idea is to retract 4mm, then switch to relative positioning
; Then move the hot end to X0 and Y250 so that the print head is out
; of the way and easier to remove object.
G1 E-4 ; Retract 4mm
G91 ; Set to relative positioning
G1 F2000 ; Travel speed
G1 Z15 ; move up 15
G1 X0 Y250 ; move head out of way.
M106 P1 S0 ; turn MosFet fan off.

just check if you have not set marlin to allow your printer go further than the max distance, or at the end of g-code you printer will probably hit the end on the Y axis.

In here:

"{IF_BED}M190 S{BED} ; set bed tempature to Repetier default
{IF_EXT0}M104 T0 S{TEMP0} ; set hotend to Repetier default
{IF_EXT0}M109 T0 S{TEMP0} ; set hot end tempature to Repetier set point "

let your slicing software do this job. I think is better set this parameter on slic3r/cura/simplify3d... than on repetier-host.

And i would set the travel speed to 3000

Vinicius795 Thanks for the thoughts
I agree with you, these are "default" g-codes that are stored in the slicers.