I thought there was a problem with a massive stretch of West Africa being desert?
I think you meant Asia Minor, and Gaul would feel awkward what with the gaulbros we have.
You're right about Syria, Germanic, Dacia, and Egypt.
Well...maybe not Egypt. I don't think we need to conquer them, we might be able to straight up talk them into joining The Republic.
IIRC there's going to be a good time to head over there in the next 5 years or so when rule falls to Bernice III, at that point we could probably talk her into turning Egypt into a client kingdom in exchange for general backing of her reign. Oh, and she would normally need a husband to act as co-ruler, but that can be tied into the governer. So she's free to marry/fuck as she wishes while the 'roman ruler of the year' acts as the counterbalance filling that male role.
It also sets a decent precedent and incentive for client-kingdoms joining up of their own free will.
On the client end of things, joining the Romans doesn't seem to mean total subjugation. On the Roman end of things, it means less bitching and/or rebellion when they've taken over, and unquestioned total control whenever a child ruler comes into play and/or the royal family inevitably dies out.