"no heta.m bhante", is that a form of hetu?

i always assumed it was, but in DPR i didn’t see it in the declension table. the closest match seems to be for hetu accusative it has “hetu.m”.

in anatta-lakhana sutta the monks answering “no reason, bhante” seems to make sense. is that correct translation, or does heta.m mean something else?

No, it’s a different word: no h(i) etaṁ, i.e. “no indeed”, or “that is not so”.

thanks bhante.

is there any reason in sutta central pali script why we shouldn’t adopt conventions like this:

“no h’etam bhante.”
“n’etaṃ mama. n’eso 'haṃ-asmi. na me-so atta.”

instead of:
no hetaṃ bhante.
netaṃ mama. neso haṃasmi. na meso atta.

pali is hard enough to learn as it is, apostrophes and hyphens at least give us a hint on WHERE in a word is a good starting point to start guessing letters to look up in the dictionary. and they’re easy enough to delete automatically with script when we want to display the suttas in the standard unreadable way everyone has adopted as convention. it’s an oral tradition, so written script can be anything we want it to be that can properly communicate without losing information.

i assume something like this:
is to convey that it’s a compound word. we can achieve the same with

i assume that
"n’etaṃ mama. n’eso 'haṃ-asmi. na me-so atta."
na etaṃ mama. na eso āham-asmi. na me-so atta.
not this (is) mine. not this I-am. not my-he self.
but that’s just guess work on my part working backwards comparing existing english translations. “na meso atta” could have been “not ram self” or maybe “na m’eso atta” -> “na ma-eso atta” -> “not not-this self”?

If you go to SIDEBARCONTROLS and click k-ā then, hey presto!, the words will be broken up by syllables, and the long syllables are underlined.

That’s as much as we can do for you, I’m afraid. The other kinds of changes you’re suggesting lie under the heading of editing, and depend on the choices made by those who prepared the Pali text.

If it’s any consolation, you’ll get used to these things quickly, they’re not very complicated. Just spend some time working with compounds and passive constructions, and when you come back to such elisions they’ll seem like a blessed relief!