Regarding Permadeath and buying Resurrection:
I may hate losing units, but I love permadeath! I also think that flagging certain armies for pvp and others not is ridiculous. That's like saying, "Oh I'm sorry bandits who are after my trade wagon with a pile of gold in it, I have a pvp off flag flying above it. Why don't you go attack that heavily armed, well equipped, highly trained, army of Godzilla killers over there? It has a PVP flag on!" I think the system is fine as it is for now, with the exception of the D/C exploit where the person who disconnects keeps their entire army but the other person suffers losses. If there is a D/C either the person who D/C should suffer losses, or neither player suffers damage or losses.
I do like the idea of controlled retreats though, if there was a designated area where to retreat to, like the border of the map, then perhaps leaving a unit in that area for a certain amount of time would retreat that unit in its current state. This would allow us to tactically retreat heavily damaged units, or our entire army altogether, but also allow the opponent to pursue and destroy said units. This in itself would become a major thought process in it's own right - how do you organize a retreat with minimal losses? If you are losing the battle, then it is inevitable that you will suffer losses, but perhaps you can use some surviving level 2-5 units to cover the retreat of some heavily damaged level 10-20 units. level 2-5 are easy enough to train up again, whereas level 10-20 take significantly more gold and time to retrain, so obviously the level 2-5 unit would be acceptable losses. When the battle ends, the retreated units join the surviving units to form the surviving army at the end of the battle. VOILA! I think contrary to Total War, that retreating out of a seige battle as a defender should be allowed as well. By surrendering the city, you allow them to destroy and pillage the city as the enemy wishes, but you save your army, and if you're lucky maybe you get to counter attack and exact revenge upon your foe.
You have to remember that the game is still young, and not everyone is ready to go out and start to PVP. I think you can expect PVP to flourish when alliances are implemented, and the exploits dealt with (100% resist - apparently still not quite fixed, D/C).
Resurrection would be an interesting topic to come back to if/once undead is released. I would love to see a game mechanic that would allow me to resurrect a dead unit of orcs as skeletal warriors or fallen orcs or something, with maybe 1/2 the level and cleared skills? I dunno... like I said, it's just an afterthought.