60-120 minutes works for most people. Shorter sessions rarely give enough time to reach flow state, while much longer sessions without breaks tend to reduce output quality.
Anything requiring sustained, undistracted focus: scriptwriting, editing, thumbnail design, strategy planning. Replying to comments or scheduling posts is shallow work, not deep work.
Yes for most creators. Deep work is mentally taxing; more sessions without adequate breaks usually leads to declining quality and burnout rather than more output.