I know I have not commented for a while, something I apologise for.
An awesome series of updates, Mett. I still come here every day to read updates, and every now and then I read the whole thing from the start again and I am SO impressed of how you seem to have woven in things that were there from the start into the story. Thigns makse so much more sense when you read it all in one go, which is a superb quality in my book.
I still hold that you should try to get this story published once you are done with it.
Alright, enough general praising, down to the basics.
Right now, the Emperorship IS the army. I think Remus has nothing to fear from the schemers of the senate. He does not really need them as long as he has the army, but they certainly need him. The only two men with real influence, Selenus and Claudius, are able and loyal men, and Clausius has proven before that he is no schemer. A Dalmatian General might, perhaps after a successful campaign against the Ostrogoths, start to gain power and desire the throne, but that is far into the future, and the way the Dalmatians submitted, I don't think they'd put a dagger into the back of the man walking in front of them, at least not until there's less enemies in front of him. Amazing how common enemies can unite otherwise infighting factions, eh?
The Imperial Guard is changing for the better I think. Having soldiers rotating in and out of this duty, and having it as a reward for the best and most loyal soldiers is the right way to do it. They will not be in the same place long enough to start installing their own Emperors (hopefully) and they'll be an elite reserve in the centre of the Empire in case they are needed. Also, I am sure it will serve as an inspiration and morale boost for the rest of the army ("We can be guardsmen too, if we fight and behave disciplined!").
Hesta is intelligent, strong-willed and streetsmart in the halls of the nobility. And she seems to be making a concious effort to be a good wife, or at least be on the right side of Remus, which is a good sign. She has achieved among the highest statuses she can, and she can really only become more powerful if Remus and the Empire does - meaning that allying with an Anti-Reman faction or trying to make her own would net her less power than keeping with Remus. She's smart and bound to know this, so I think she will attempt to expand her own power, and use it to help Remus in order to keep it (I don't think he'll hesitate to remove her should she be a liability, and I think she knows this too). If they can develop a friendship, political partnership and mutual trust and perhaps, even some love, although in Remus' case I'd see it more as affection, I think they would make an excellent dual Emperorship along what was used in the east, one for the politics and scheming of the home front, one for the military and all the wars, only that they are Emperor and Empress instead of two Emperors.
And Regulus plays for the other team, so I don't think he'll marry someone prominent who could complain about the lack of fulfilment of the marriage.
Excellent story Mett, looking forward tremendously to the next update.