Endstop coreXY

Hey all,

i'm creating my own 3d printer with the coreXY theory.

i'm almost finished with the mechanical part of the printer and now i'm reading about the electronic/arduino part of it. (i know how arduinos work (playing with it for 10 years now) thats why i like to use marlin, and its cheap )
but my quastion is if one of the steppers skips a step the Y axis wil be crooked thats why i want to have 2 endstops on the Y axis so when it homes it corrects it self.
i know the X axis will also be crooked but the X axis endstop will correct that.
is there a feature inside the marlin firmware that can do this.

so
2x endstop for Y axis
1x endstop for X axis
1 or 3 x endstop for Z axis (maby i will add the auto bed level feature)

and offcource i understand the stepper should not skip a step, but i think it will be a pain in the a$$ if i need to do this manuel all the time, durring calibration the max speed for the printer.

and is there a tool change feature on marlin?
i like to have my E3D verion 6, volcano and a dremmel on it.

kind regards, Emile B