A few things in no particular order:
1. Purely out of curiosity, do you know Italian, Andy?
2. Sort of going with question 1, can you explain why ingrediamini is subjunctive based in the Italian? If not, can you just explain your reasoning there?
3. There should technically be an "et" after potestas divina; I'm not sure if you can go without it or not.
4. 8th line: "si non factae sunt aeternas." Would that be "si non factae sunt aeternae"? It seems like you don't need to be quite that long, though I'm not sure how to make it shorter without making it too short. :wondering:
5. (Thanks for teaching me this Cato!) There is a distinction between si non and nisi (both take subjunctive I believe, by the way.) It's easiest to explain with a simplified example:
Si non cenem, irer.
If I do not eat dinner, I may grow angry.
Vs.:
Nisi cenem, irer.
Unless I eat dinner, I will* grow angry.
However, "Si non cenem, moriar" is really almost like "Si non cenem, moriar, sed etsi cenem, fortasse irer." In other words, nisi is a concrete "If I don't...then..." whereas si non is more like "If I don't...then...but even if I do, it might happen anyway."
*In English this would normally be future, but the Latin is subjunctive because of the conditional.
I think in this case we would want nisi, so the full line would be:
nisi factae sint aeternae et ego in aeternum permaneo
Hopefully someone will find this thread and correct any mistakes I made here, as I'm sure I made at least one.
6. Elementum is neuter and you're using a plural, so elementa illa...quae...facta
7. Possibly an "a" before divina omnipotentia; without macrons it's a little odd, and it's possible to interpret the line as "Here, I, divine omnipotence, was raised."
8. Continuing on 7, I think it would be statutus, since the speaker is Dante himself as far as I know; simply doing this might make the "a" unecessary.