Reading through all the posts here made me want to do a new playthrough of KBAP. I haven't done that for a while and found that I really missed the game.
So I picked up a Warrior, selected Impossible and went for it. I must admit that the warrior gets a pretty easy time in this game, at least in my opinion. The start is dodgy, you may have to replay some battles later in order to ensure quick 50 no-loss victories (the requirement for the Great Tactician medal, or whatever they will call it) to get a huge boost to the leadership very early on which will ensure your easy-going through the starting islands. Still, compared to the start with a mage, it was a breeze. Just for a reference, the mage starts with Flaming arrow and Fireball scroll, and it is some time before she can get the fireball spell itself, and even if she does, it isn't much use early on in impossible (I also have a mage started on impossible, so I have a certain ground for reference - even with +200 leadership helm, +150 leadership belt and +250 leadership batton she struggles).
Since this was my first playthough on impossible, I wasn't much aware of the hardships at hand. This is why I can give a few pointers to the people who will decide to try it out (they work if you play through the first time as well, they will work for me from now on):
1. Have a clear idea what kind of army do you want. Do not spend money on a new unit simply because you have the money right now. You may need it later. I made the mistake to buy a ton of necromancers early on, which I used in only 10-20 battles and had to babysit them, since I couldn't resurrect them. I also made the mistake of buying a ton of Emerald Green Dragons and Assassins, which I barely used. Do not make my mistake

2. Read the quest info thoroughly. They provide valuable information that you will need when you do the quest. They also open up new quest possibilities, so save before talking to a quest giver.
3. Be a cheapskate. Do not spend money on items that you will not need later on - or you are unsure whether you will need them later on, for that matter. You may spend 60k on items and troops just to see on next island a piece of equipment that provides 10 might/mind/magic runes, for example, which is a must to buy and use, as it will speed up your development very quickly, especially in the early levels. You will rue that mistake.
4. A general rule of thumb that will ensure that you will never run out of cash is: never lose units worth more than 3/4 cash you get from the battle (since you will advance in levels and you will need more troops). If you must lose more units (for example, in boss battles, castle sieges, etc.), make sure you made up for that in advance.
5. Make sure you do as much victories without casualties. This will help you amass a sizeable amount of money that will help you early on.
- another way of circumventing this problem is to use scapegoat units (meaning expendable units) that are easy to recruit in each area - like Executioners (the new purple demons, always retaliates), Royal Griffins (a new type of griffin, always retaliates), Paladins (resurrection and a great tank), Ancient Ents (tons of HP), etc.
- as a Paladin, you have one great trick up your sleeve. The resurrection skill that I had so stupidly neglected and ridiculed can be used to your advantage big time. Granted, it alone costs 42 mind runes to master, but it pays off big time. With it, you can use a scapegoat troop in each battle, which, even if destroyed, will come back to life after the battle. It counts in the losses, but unless you're going for a no-loss victory, it isn't much of a problem
- as Calinda suggested, paladins + phantom spell is wicked.
6. Learn to love your dragon, especially if you play a Warrior. Use it anytime you can. As a Mage, you should be more cautious with it, as using it more often will have him gain experience quickly, which may surpass the overall rage amount you have.
7. Be on the lookout for "easter eggs" - or things that have something in common with King's Bounty: The Legend game. There are a few of those here, and they are fun to spot.
As for my playthrough, I must admit that it was riddled with mistakes, but in the end, it was fun. I didn't find some very useful spells until lvl 30+ - like Target, Sacrifice, and I never found the Time Back spell (just my luck I guess), even on Rehau island, where I found it in the last 2 playthroughs. For example, I went to Tekron island 4 times, while in essence one can do it in 1, maybe 2 tries at most. It also seems that I once again missed out on 5 quests, and for the life of me, I don't know which they are. I probably made some bad decisions in the quest dialogues, since this is my 3rd playthough with 82 quests completed. I also ended up with 230 out of 282 battles without losses. Not bad I guess. Could have been more, but I didn't buy a lot of items that can be upgraded - that improves the battle count and provides cash, but I did poor army choices on a few occasions and had to re-stock, so I didn't had a lot of extra money... shame on me. The losses are sizeable for only 52 battles with losses, but most of those were scapegoat units I had to use.
Another thing I noticed is that I get more than enough rage in combat to use the stronger dragon abilities all the time, whenever they became avaliable even with +40% rage income when troops exchange blows (there is also a +60% option).
So in the end:
Score: 1651
level: 54
Atk 36 / Def 27 / Int 23
Rage 119 (165 max with proper equip) mana 50 (65 with proper equip)
Battles 282
Losses: 4992
Enemy heroes killed: 76
Bosses killed: 6
Damage - by troops: 78%; by Spells 0%; by Dragon abilities: 22%
Final Dragon lvl: 59
And of course, I do hope I'm not pouring too much salt in the wound with this post, as people are still waiting for the English release...
P.S> It would be really, really great if the current fan manual (or at least I think it is fan manual) is translated in from Russian to English with the launch of the game. It has everything in it - from skills and attributes, through monsters, game objects, pointers to game mechanics. An it's 217 pages of content. Actually it is the best manual I have ever seen. Extremely descriptive.