Hello kirtipatial24722,
The 60fps are OK to support on iMX8QM, the DPU is enough to support it. For GPU, there is no limitatiom on width. For video render, it is also OK, after VPU decoded the original video file, the DPU and GPU will be used to render, so it is OK.
eDP 1.4 covers eDP 1.2.
Regards