Probably my biggest concern was that the colony is practically broodless. I checked on them last Sunday and they had all stages of brood. Now, the only brood is capped. I searched the entire hive and couldn't find any eggs or the queen. The population, however, has greatly increased even since I last opened them a week ago, so, I know they didn't swarm.
Nathan, I don't know for beekeeping in Florida, but in much of the rest of the country about now, most hives are broodless. I haven't seen eggs in my hives for weeks. Also, when a queen stops laying she can slim down a lot and be harder to locate, especially if they're not marked. You didn't say if she was marked or not. I suspect also that when they've stopped laying, they tend to be more skittish- hiding in the corners of frames, not marching around the frames inspecting cells and preoccupied with laying like they usually are. I mean, if they're not laying eggs, what do queens do?
I think you're right, it's unlikely they swarmed this late and if they did I'd expect to find swarm cells. What do your other hives look like? Are they russian also? Do they have eggs and open brood?
I don't know what that noise was you heard, if it's even relevant. As for being a bit hotter than usual, that could be due to a number of things. Without open brood to care for, your bees might be inclined to fly more. Dunno. I've always found queenless hives to be unhappy, a bit more unsettled maybe, but not necessarily more aggressive. On the contrary, they're usually more lethargic- not the usual level of activity i.e., a lot of bees with nothing to do. The hives also tend to make an unhappy discontented "roaring" noise. Doesn't sound like that's what you heard though.
I can't say if your hive is queenless or not, but right off, the absence of eggs this time of year isn't to be unexpected. You might want to wait for a nice sunny day and check again, carefully, without smoke. She'll be on a frame with a lot of bees.