lojong1 wrote:a few quick trivia questions to keep me off my toes and you on your bum

Are sabba and sabbe the same word different number, i.e.:
sabba = nom. sing.?
sabbe = nom. pl.?
Or does one mean 'whole', the other 'all/every'?
sabba is not a proper Pali form - it is the undeclined form of the pronoun. The only place you would find it is in a compound, e.g.:
sabbabuddhānubhāvena sadā sotthī bhavantu te. (sing)
sabbadānaṃ dhammadānaṃ jināti. (pl)
in which case, it can be either plural or singular, as signified by the noun in the compound.
Perhaps you are thinking of the form "sabbaa" or "sabbā"?
If so, sabbā and sabbe are both pathamaa (nominative) and dutiyaa (accusative) plural, one being masc. and the other feminine:
satañca gandho paṭivātameti, sabbā disā sappuriso pavāyati. (fem.)
ekaṃ nāma kiṃ"? "sabbe sattā āhāraṭṭhitikā
Are both terms used in different versions of anapanasati and satipatthana in different countries/canons?
Maybe I'm missing something, but I'm going to go out on a limb and say that sabba is not used in any canon, except when contracted in a compound; sabbaa and sabbe are used in all, as explained above.
Can 'passambhayam' mean: calm/calmed; having calmed; having been calmed; being calm' instead of 'calming'?
Passive past participal or gerund or something else instead of whatever it usually is translated as?
According to the vinaya commentary:
passambhayaṃ cittasaṅkhāra nti oḷārikaṃ oḷārikaṃ cittasaṅkhāraṃ passambhento, nirodhentoti attho.
passambhayaṃ kāyasaṅkhāraṃ assasissāmi ... pe ... passasissāmīti sikkhatī ti oḷārikaṃ kāyasaṅkhāraṃ passambhento paṭippassambhento nirodhento vūpasamento assasissāmi passasissāmīti sikkhati.
I think passambhaya is a past participle already... meaning "made calm". So: "I will breathe [so that] the bodily formations are calmed"
You can't just "make" it a gerund, though

That would be passambhetvaa:
pubbe khvāhaṃ, bhante, gelaññe passambhetvā passambhetvā kāyasaṅkhāre viharāmi, sohaṃ samādhiṃ nappaṭilabhāmi.
Best wishes,
Yuttadhammo