First run was Vlandian vassal. Was the main "learning" playthrough. Liked it fine. Had a Vlandia/Battania/Imperial/Sturgian mixed army.
But I think I'm enjoying second run a little more, if only because now I understand the leveling system a little better and am developing character more efficiently. It's an Imperial "merc" playthrough so far, at least as far as game mechanics go. RP-wise, I'm conceptually a semi-independent Imperial force dedicated to the Empire but trying to stay out of the internal civil wars. So I hop around among the 3 empire factions helping them all with "external" wars against the non-imperial factions.
Kinda set myself some rules: 1. Imperial faction troops only in own party (can't fully control what the companion parties do). 2. Spouse must be Imperial. 3. Can only merc for one of the three Empire factions. 4. Only attacking non-Imperial armies/parties. None of these are particularly hard or limiting, just RP stuff. Eventually will go to vassal stage, which will necessitate dropping "rules 3 & 4".
As far as the pesky main quest, I went as far as assembling the banner, just to ensure the whole thing didn't expire. But now just ignoring it...I don't need the Conspiracy thing chiming in every 20 days for years. If this playthrough ever goes long enough that one Empire faction remains and is big enough to conceivably take the whole continent, then maybe I'll give that ruler the banner and see how it goes. Have zero interest in forming own faction (and will stay that way until all the diplo & kingdom management stuff is worked out...at current stage of the game, I'm kinda puzzled why TW even gave us the "own kingdom" option via main quest at all).
Biggest setback so far: My wife Sora died in childbirth (on her eighth child). I had known that was a possibility, but hadn't really thought it through, I guess. Discovered the Achilles' heel of using wife for a clan role (in this case, Quartermaster). She had developed up to almost 250 steward, so party size took an enormous hit. Now I'm frantically running around the empire trying to find a gal with good Steward and compatible-enough traits to get through the dang persuasion checks. Even with unabashed save-scumming, am getting nowhere with Panalea so far. (The thought occurs to me, this potential problem can only occur with a wife; female character with husband wouldn't have to worry about it. Afaik, a female player character cannot die in childbirth...is that true?).