If I was someone not playing EU3 over and over again for many years (until DW...) I'd say these changes are all good. Don't get me wrong, I am not saying this DD is bad, nor do I say it lacks innovation. Maybe it's just me but I thought EUIV will carry the EU franchise to the next level by not just replacing features but by adding new ones.
One thing I was hoping for was a realistic population calculation which is related to every aspect of your empire - some microcosmos inside your economy. I think people don't realize the importance of the population and how war is connected to this. At least I didn't ever think about it until I saw the "Game of Thrones" TV show. In that show you could see the Stark son dealing with Winterfell business while his brothers are out fighting. I especially liked the audience scene where the city people came to him and told him about their problems because of the war. I felt like I found a new star in the sky as I never thought of that...
But indeed war changes everything: When your country is at war, when your able men are at arms then there is not many people left at home to care for the farmlands. This leads to food shortages and increased death rates.
Now why should you care? You should. Because less people means less taxes. Less people means less workforce. Less people means less manpower for your army.
But in EU3 and to my dislike now also in EUIV you don't ever have to worry about that.
Your empire has a population of say 1 million. You lose an entire stack of 50k men to some enemy but my total population doesn't change. I can go on and on with this procedure until my manpower pool - which is as well not linked to the population calculation - is exhausted.
I understand that calculations like this were a little bit too much for EU3's time. But now we have the chance to add all this stuff in. This is in no way complicated, just complex. For me EUIV looks like EU3 with better graphics and some real great features.
Someone who played EU3 on a more casual level EUIV still looks awesome. But it doesn't take the logical neccessary steps to carry it to the next level.
So this is what I'd like to see in short:
- manpower connected to population (you lose population if you lose your armies)
- tax connected to population (stay at peace and your people will not die and thus you'll get a bigger population and more taxes. You have to think carefully about going to war or not as peace might be better for you)
- max population connected to your agriculture tech level. If your population is higher than your support rate death rate and diseases will increase and your population and economy will suffer. Now could be a good time for war... (Actually this thought was even historical correct)
- province population reduces if a regiment is recruited at that province (1k army = 1k less men in that province)
- higher population increases the chance to get better advisors/envoys/generals simply because you have a bigger variety inside your realm