Commercial aircraft must be capable of continuing a take-off if the critical engine fails around V1
ie FAR 25 certifications. The key is the certification basis not whether the aircraft is being used for commercial or non-commercial activities.
On something medium sized such as Airbus 320 family, on most days from most international airports, the RTOW will be same as the MTOW
Depending on the particular aircraft, generally providing that the elevation is somewhere near sea level and the OAT somewhere near ISA. As elevation and/or ISA deviation increase, WAT limits will reduce the weight regardless of runway length, terrain and other considerations.
Even with ideal Met the RTOW gets limited by LW.
This will depend on the difference between TOW and LW and the sector distance. Generally a consideration for shorter sectors.
MTOW as envisaged here is structural.
MTOW will be determined by whatever of the various certification design weight issues results in the lowest weight. Often, but not always, that will be a structural consideration.
In ideal condition without any restricting factors OEI is not an issue since it is factored.
It is not clear what you are referring to here .. perhaps you could amplify your comment ?