Marlin firmware for rostock does not use min endstops. You do not need to even mount them on. Only max endstops are used and typically only for homing (depends on ENDSTOPS_ONLY_FOR_HOMING). My branch of Marlin leaves top endstops active all the time.
You must get endstops with M119 working so that:
* min endstops are ignored (or always not triggered)
* max endstops work (are triggered if and only if the microswitch is pressed).
It does not make sense to try to move the motors before you get endstops right with M119.
I do not know anything about prusa i3. The only printer I know well is the clasic rostock.
Belts of course are not a problem which was shown on the video. I only mentioned it because I saw your pictures and wanted to give you heads up. When belts are loose you can get tooth skipping (you can even see this with your eyes) or if they are not tight enough you get less precise corners especially when pringing with higher speeds. Also prefere belts with steel core instead of glass core belts. It makes a difference for long belts (which are on rostock).
My belts are tightened with force of about 120N, that means the static tangential force on stepper axe is about 240N (which is about half the maximum the stepper can handle in long term). Even 120N is probably not enough but it is already acceptable. You will see this when you actually start to print.
You must get endstops with M119 working so that:
* min endstops are ignored (or always not triggered)
* max endstops work (are triggered if and only if the microswitch is pressed).
It does not make sense to try to move the motors before you get endstops right with M119.
I do not know anything about prusa i3. The only printer I know well is the clasic rostock.
Belts of course are not a problem which was shown on the video. I only mentioned it because I saw your pictures and wanted to give you heads up. When belts are loose you can get tooth skipping (you can even see this with your eyes) or if they are not tight enough you get less precise corners especially when pringing with higher speeds. Also prefere belts with steel core instead of glass core belts. It makes a difference for long belts (which are on rostock).
My belts are tightened with force of about 120N, that means the static tangential force on stepper axe is about 240N (which is about half the maximum the stepper can handle in long term). Even 120N is probably not enough but it is already acceptable. You will see this when you actually start to print.