I have been watching the thread on "middle" (μέση) and "passive" (παθητική) and am happy with its general direction.
What remains for Greek teachers and classes to do is to choose the best διάθεσις (disposition, perspective, "voice") for each common verb.
For example, in compound verbs with -στῆναι/-ίστασθαι 'stand-+', the eta-aorist/middle is the correct common verb.
Like ἀνίστασθαι 'to be standing up'.
The uncompounded verb is 'temporally suppletive' and tricky: στῆναι 'to stand' and ἑστάναι 'to be standing'.
The point in the above is that στῆσαι ἱστάναι (ἵστημι) will probably not be the first diathesis needed, and should not be the default first presentaton to a student. "set up, place, stand something" is a less frequently used verb. ἔστην ἔστη is more common and useful than ἔστησα ἔστησεν.
Many verbs need to be presented separately.
Depending on the texts to be read, I would suggest that the default presentation of *αιρε should be
ἑλέσθαι 'choose' [etymologically: 'take for oneself'] αἱρεῖσθαι 'be choosing.' Choosing is a common vocabulary item in a learning situation. (As in 'choose the most correct answer.') ἑλέσθαι is more common than 'taking/killing' ἑλεῖν αἱρεῖν.
STudents need to be able to use and to respond to ἑλοῦ and ἕλεσθε directly, immediately, and without "parsing". (Not that they won't be able to "parse" when asked, but "parsing" is not a communicative activity and requires stepping out of the language and into a second-tiered metalinguistic environment.)
Perhaps a little trickier is deciding when and how to introduce the synonym ἐκλέξασθαι ἐκλέγεσθαι 'choose, pick out'. Also, in this case it is the "middle" disposition that should be chosen for presentation.
The main point in all of this is for teachers to reflect on what they actually want to do with some verbs and then present the best διάθεσιν for that verb.
"παῦσαι ποιοῦση ἐκεῖνο/ παῦσαι λαλῶν !" Here, παῦσαι, of course, is a middle and is probably much more practical than the active παῦσον. [Yes, παῦσαι 'imperative middle' and παῦσαι 'infinitive active' are homonyms, but the middle is used with the participle of the activity to stop.] Let the student learn ! παῦσαι ποιῶν ἐκεῖνο ! in context.