Kirk states they have 2 hours of oxygen left but it is easy to miss if you aren't paying attention. That puts an upper limit on how much the shuttle is trailing the max warp Enterprise while coasting.
No, it doesn't - because the coasting plays no known role in the survival of Kirk.
There is zero indication that Spock would wait for the shuttle to glide to transporter range. For all we know, the shuttle is already well within that range, and possibly tractor range, too, since as said, Spock makes zero reference to anything to the contrary.
There is also zero indication that Kirk needed to wait for any length of time before getting beamed aboard. To the contrary, he has a comm channel to the ship now, but only gets a situation update once the beaming aboard is completed.
The only real wait in that scene is for the security team to arrive to arrest Spock... Which is reason enough for Spock to put certain things on standby.
KIRK: Scotty, reverse engines. Slow us down.
Which is what Kirk wants done when he has just been told that they
cannot slow down. So whatever the reversing is supposed to achieve, it is
not the standard method for slowing down, because that one already failed.
Basically, Kirk having to call Scotty instead of just having Sulu do the slowing down is analogous to how a seagoing ship might be forced to steer by throttling the engines on two different screws when the rudder fails. It's exceptional, and inefficient, and not really sustainable.
In "The Menagerie", too, Kirk wants the engines "reversed", but his desire there is to prevent the ship from getting underway, from present standstill. It appears that "reversing" there at least means "shutting down" rather than "running in such a way as to make the ship move backward aka decelerate". Or perhaps it means "dropping the anchor" (in subspace?), something the warp coils might be eminently capable of doing, in this weird Trek universe where there appears to be an absolute frame of reference that one can grab a hold of.
You and I have a very different way of interpreting dialogue
There is that, yes. But apparently the writers also have a very different way with the words. Including "reverse".
As for landing party makeups, it might well be there's a requirement for a minimum team, puttting extra significance to those times when Kirk insists on going alone. Who goes into that team might then be less important than having, say, sufficiently many people to carry one or two wounded out of a dangerous situation. Or one to provide firecover when the second calls for medevac beamup for the third, or whatever.
Timo Saloniemi