I say, good plan. But, since you ask... - a tentative roadmap I would suggest. 
This is a good 1.0 release, as games go. A veritable success. But the goal is not just vindication, is it? I would venture a guess that the goal is to make a great game, maybe even a revitalized franchise. Which requires considerable resources. And that means a non-negotiable commercial success to generate those resources. So...
1. Squash the remaining bugs. Really. And fix the tooltips. For the usual fans they are not so meaningful, and we know how the game really operates. But for a more casual gamer they would be a quick turn-off.
2. You think you squashed the bugs? Potion of might actually working, potion of essence giving just 1 essence instead of 2, tooltip for Warrior not misleading about the attack bonus and the "Path of the Warrior" he puts somewhere on the mantelpiece, all that small silliness gone? Come on now, think again. Of course you didn't squash all the bugs. You definitely didn't squash the things you sincerely think are not bugs. But you are no longer making a game for yourselves and some 10-years-in-waiting die-hard fans. So get serious and bring a couple of fresh eyes, or two. Manual testers who see the game for the first time ever, just two would suffice. And tell them to be absolutely fascist about testing the product. You will be surprised what they will flag as a bug.
3. Now you fixed not all the bugs, that is not feasible, but all the important ones and most of the turn-off-a-new-customer ones. So it is time to do a usability pass.
Remember the two guys you hired for a quick testing gig? Tell them to tell you what frustrated them a bit. The game is eminently playable, but there are always those small frustrations. Not knowing exactly how much each individual unit costs in maintenance? Getting a city expand near a forest but not being able to build a frigging logging camp because the woodcutters refuse to bother if the forest is not just near the central plaza? Henchmen sometimes getting killed and sometimes just getting injured, seemingly randomly? Being able to equip one single ring from general inventory on a six-guy unit, and irretrievably losing the said ring when the unit gets killed in battle? Having access to Giott's Quiver and the very powerful Heart of Flame from the get-go because they were imported to the game without adding reasonable prerequisites?
Make a list. Evaluate the list. Prioritize the list. Improve the top10 issues. See how it goes. Then improve top20. Then keep the list and sneak things from it into future releases.
4. Now the game is ready for releasing it into the general populace. So get that marketing budget cracking. Before it would be a waste, but now it is the right time. Get new excited gamers on board. Get some new cashflow... and some new opinions.
5. Filter the new opinions. Do not get pissed at them, they can't really help themselves. Filter the opinions for usable info. Make another list. If things overlap with remaining items on the previous list, you have some winners just there. The other items - categorize and prioritize. What can be fixed/improved upon quickly and cheaply? What goes into a future DLC? What goes into the "I'd love having that done... some time, in a few years"? What is a nice concept, but really doesn't fit into existing mechanisms so we'll just keep that in mind for future reference? And start working on the winners and on the first category.
6. Now you are ready to get serious on the first bona-fide DLC.
7. Go for it. Keep an eye on the cashflow, feature creep and overblown expectations. Before you add a completely new feature, flesh out the existing ones. More and better goodie huts, quests, items - that's good at this point. Reimagining and improving city building or dynasty building, enabling on-the-fly modding, adding depth to existing mechanisms - that is also great. You will get fancy with totally new stuff in the third DLC. Not a flashy run, but very sustainable. Momentum building. AKA common sense.
8. Profit. 