The "pebble-worm" derivation seems rather doubtful. Of the etymological dictionaries, Frisk and Chantraine accept it, but Beekes says it "should be forgotten". I can't find any direct evidence of a word δρῖλος meaning "worm"; here's what I've found:
Hesychius lists a word δρίλαξ meaning "leech", which is pretty close.
δρῖλος itself appears to be a δὶς ...
If you wanted to break explicāndum down into morphemes, it would look something like
ex -plicā-nd -um
"it should be unfurled"
The -nd- in the middle marks the gerund and gerundive. I would personally group the -ā- in with the verb stem instead of with the gerundive suffix, but an argument could be made either way on that.
The names as they appear in that document seem to be "Dominum Conradinum Tognionum", "Domino Jacobo Togniono", and "Dominâ Malgaritâ Biveronâ". The first is inflected into the accusative case, the second two are inflected into the ablative case.
When mentioning a Latin name in English, the usual form used is the nominative case form. In the nominative case, ...
The short answer is this;
The -i ending is used to indicate a group of people, when they are the chief participants. There is a useful check, that the verb will end in -nt or -ntur.
The -i ending is also used to indicate possession (genitive): 'the house of,' the 'the gift, donum, of;' and relationship, as Filius Tognoni, 'Son of Tognonus,' Mater Biveroni,...
My guess is the following: the appearance and disappearance of liquid consonants is very common among languages, for instance, latin parabola became palavra in portuguese, and mīrāculum became milagre, in both these cases by a process we call "metathesis". The word indeed came from krókē + drîlos and it changed by means of making its articulation easier. So ...
I'd keep my advice simple on this:
Do anything that you like.
I mean it; the rest is just a commentary on this.
If you enjoy doing something and can think of a way to combine it with Latin, go ahead and do it.
You can create or recreate — if drawing your own comic in Latin sounds like too big a project, take a comic and write new texts in Latin.
If it ...
I think that the prefix sub-, as you yourself have mentioned, fits the bill quite well. Lewis and Short list subabsurdus, subagrestis, subalbus, subaccusare, subirascor, etc., to which I could add subfuscus, a favorite of Patrick O'Brian.