There would seem to me to be far too much complexity in the considerations being put forward.
The aircraft is certificated to be able to execute a missed approach in the landing configuration. This can be interesting on some aircraft - I think back to that lovely old Piper Supercub with hands and feet pushing the stick forward - but nonetheless it can be done within reasonable stickforce values.
I suggest that a missed approach with an immediate flap retraction at flare height is both silly and poor practice on a small single pilot training aircraft. Why not execute the missed approach and then, when at a suitable height, reconfigure the flap, trimming as necessary ?
For a touch and go, if the runway is short, one ought not to be doing the exercise anyway. Otherwise, a consistent procedure is appropriate to minimise student confusion. On a small trainer, it really matters little whether the flap is reconfigured before taking off again - or at a safe height following liftoff (as with a missed approach) and, if the former is the procedure to be followed, the IP ought to do the reconfiguring and retrimming (where practicable) to allow the student time to concentrate on the main elements of the practice manoeuvre.
This presupposes that
(a) the student is thoroughly briefed on the need to use whatever stickforce is necessary to effect the required manoeuvre
(b) power is increased without undue delay during a touch and go, and first of all, on a missed approach.
[This message has been edited by john_tullamarine (edited 17 May 2001).]