Non stetur

Isn’t “non stetur”, meaning “it should not be kept/let stand”, perfectly fine and grammatical here?
Nonnè est hîc usus per “non stetur” bonus et approbatus?

Wouldn’t “sto” only have a impersonal passive and thus be ungrammatical here where it’s intended to have a subject? I’m not sure but wouldn’t it mean something like “let there be no standing” or something similar?

(Should it be “ne” instead of “non”? I thought the former is used with the subjunctive in this context.)

I think the “non” is OK, at least, given these examples:
Credo bonum esse usum “non” saltem participii negativi, per his videlicet:

Aquinas, "> Est ergo contra ius divinum prohibere quod eius iudicio non stetur si sit infidelis…> "(In Ep. 1 Thomae ad Cor. c. 6)
"> si arbitri sententiae non stetur> " [“if the sentence of the arbitrator is not adhered to”] in H. Roby, > Roman private law in the times of Cicero and of the Antonines > (1902) > http://www.archive.org/details/romanprivatelawi01robyuoft > vol 2, p.320.

Maybe the above unknown writer is being rather clever, or maybe it is a grammatical mistake.
Forsitan nimìs callidus scriptor supradictus et clancularius se ostendat, aut verò is benè erret.

But the subjunctive in those two examples is being used as part of a conditional clause. I thought that when you use a subjunctive as a third-person imperative, as the original example seems to be, you have to use “ne”? But now that I look at it again I don’t even understand why quod + subjunctive is being used. That seems an awful lot like translating the English construction into Latin directly.

Well, you can’t accuse Aquinas (in the second example) of being English. It is more common, however, I know, to find indirect statements with the subjunctive introduced by “quod” in Later Latin and negated by “non”: “quod” + “non” + subjunctive for reported speech. You yourself refer to that here http://discourse.textkit.com/t/quod-subjunctive-construction/8475/1
En, ne accuses Thomam de Aquino (cui alterum exemplum est) anglicum esse. Clarum est quod plerùmque latinè aevorum serorum sic “quod” conjunctione verbum subjunctivo modo praecendente oratio obliqua introducitur. Hôc usu, negatio per “non” exprimitur. Tu ipse in loco suprâ citato rem testaris.

But this is not an indirect statement – it seems to me they’re using “quod” where “ut” would have been used, or in this case “quod … non” instead of “ne”. But I misread the Aquinas quote and later on he has “sed prohibet quod fideles non eligant voluntarie infidelium iudicium” so this does seem to be something that occurs in later Latin, but as far as I can tell it’s definitely off when it comes to the classical language, no?

No, this is not classical. But surely neither is it a conditional clause. Is “it was ordered” not introducing a command in indirect discourse “that it should not be kept/allowed stand” (directly “let it not be allowed to stand”). You could say it’s a substantive clause of purpose (normally with “ut”), also, perhaps. I’m not talking about “that John Mokes has…” .
Ut dicis, non classicum latinum est, nec conditionalis ista clausula, nisi fallor. Nonnè oratio oblique est haec clausula post “praeceptum est”: “quod de caetero non stetur” (rectè “de caetero non stetur”) videlicet? Fortassè ea clausulam effectûs substantivam (aliter per “ut”) vocari potest. Quod hîc dico non ad sequentem pertinet: “quod Johannes Mokes habet…”.

I never said this was a conditional clause, else I wouldn’t have complained about the non. I did misread the Aquinas example as a conditional clause (although I still the think that’s the case with “si arbitri sententiae non stetur”). But I wouldn’t consider this an example of indirect discourse, though, but I guess that depends on how you define it.

OK, sorry, I misunderstood you when you said “the subjunctive in those two examples is being used as part of a conditional clause.”
Licet, me excuses, malè te intellexi.