Write down the acceptance criteria for the project, not just its deliverables. "A working integration" and "an integration that passes these five tests" are different commitments and one of them is arguable.
If this cannot be written at kickoff, that is the finding. It means discovery is not finished, and proceeding anyway is a decision worth making explicitly.
One named approver per deliverable, with a stated turnaround. Approval by committee with no owner is the single most common cause of delay, and it is invisible in the plan.
Also agree what happens when they are unavailable. Two weeks of leave in the middle of a delivery is normal and should not be a surprise.
Long enough to settle done, decisions and change. Usually a couple of hours, not a day of introductions.
For anything client-facing, yes. Approvers especially.
Checking that the people the plan assumes are actually free.
Half an hour with your own data usually saves reading three of these. The guides will still be here afterwards.