Anyway, in the meanwhile, since you have now spent several weeks in the Empire Fanriel has acquired a basic grasp of the situation as it stands with the civil war, which people have been asking for since the beginning of the thread. I decided to make it into an informational threadmark because I couldn't figure out an organic way to put it into an update.
There are currently four major claimants to the throne of the Empire of Sigmar: Reikland Emperor Wilhelm II Schliestein, Marienburg Emperor Paulus Van Der Maacht, Wolf Emperor Siegmund Todmeyer and Ottilian Empress Anna-Louise VI Feuerbach, though of course they each just call themselves "Emperor" with no descriptor attached.
The Reikland Emperor controls Reikland, Wissenland and Averland, making him theoretically the strongest of the claimants, as those are some of the most productive and fertile of the Empire's lands, but he is held back by two factors. One, he controls Wissenland but not Nuln, which has declared itself neutral and independent of the Emperor-claimants, something that they are happy to enforce through the barrel of some very large guns. Naturally, this doesn't stop them from selling those same guns to all sides of the conflict. Two, while he is officially backed by the Cult of Sigmar, from the sounds of things in reality it's more like him backing the Cult of Sigmar. While it's impossible to say for sure all the way from Ostland, as far as you can tell the Grand Theogonist is the real power in Reikland, and the Emperor is mainly a figurehead.
Marienburg controls only the province of Westerland, and thus the smallest amount of land and population. However, due to Marienburg's mercantile interests Paulus is also the richest of the claimants, and the Treaty of Amity and Commerce makes attacking Marienburg practically impossible for the other claimants. Furthermore he is backed by the Cult of Manann, and enjoys near-total naval dominance in the Sea of Claws and in the lower Reik, threatening Carroburg and Altdorf.
The Ottilians control Talabecland and Stirland, and by your estimation are currently the weakest of the claimants, but the free-for-all nature of the civil war and the natural barriers of the rivers Aver and Talabec make invading them a difficult prospect. The descendants of the original Empress Ottilia appear to have splintered into countless branches, not all of whom necessarily agree on which are the cadets and which is the main. Empress Anna-Louise seems to be trying to shore up her position by conquering Ostermark, which used to be under the Ottilians' control but rebelled and declared itself independent. They also claim Mootland as part of their territory, but they seem to have struck a deal with the Halflings that they will be left alone so long as they sell them cheap grain and guard their section of the Aver against southern incursions. They are backed by the Cult of Taal, but their support appears to be less overt than the other Cults.
Lastly, the Wolf-Emperor Siegmund, often referred to as Siegmund Wolfborn, rules from Middenheim and is owed fealty by Middenland, Nordland, Hochland and Ostland. He appears to be an able military commander and has recently won a major victory against the Reiklanders, which appears to be only the latest in a long string of successful campaigns by the armies of Middenland, backed by the Cult of Ulric and the War-Wizards of Middenheim. However, reading between the lines, it sounds like Middenland is for all intents and purposes fighting alone: Nordland chafes under Middenlander dominance, having previously been independent before being vassalized, and takes almost as many resources to pacify as it provides, Hochland can field little in the way of troops and the moment they try to leave the province it would be overrun by beastmen and greenskins, and while Ostland is happy to pay taxes to Middenheim Elector-Count Odo von Hohenzollern has staunchly refused to send his armies south to support the Wolf-Emperor's imperial ambitions, which Siegmund is hardly in a position to force him to do. You get the impression that Siegmund is personally popular, but the war is not.