I sometimes get diplomatic messages and they always want something. Whether I give it or not, or form the alliance or not, they always end up hating me after a little while. Should I just ignore every diplomatic contact?

I think the problem is that many AI can tend to be very fickle with alliances - mostly I suspect to avoid the player gaining an easy diplomatic victory or ganging the AI up against each other. As for following through I would say its highly depends - early on provided that what they ask for won't cripple you its as based to either be on good terms with those living close to you or to be very aggressive and put them on the defence.

Thus either creating a safe front where your opponent won't (for a few turns) be threatening your cities and advance or creating an advancing front where you are taking from them or at least preventing their advance - clearly with multiple opponents chances are you'll end up with a few fronts and thus need to balance which ones you try to keep as friends and which you push against

Ok, you've got my interest here.
I'm a big fan of MoM, but the one thing that always break my fun is the broken diplomacy, and the random declaration of war that just about everyone throw randomly at me even if they were "friendly" the turn before.

I would really like to play a MoM version where I could just have foes that don't have this "each turn there is a X% chance of randomly DoWing me" thing.
On the other hand, I'm very cautious about fan-made patches, because they tend to also include lots of tweaking that fits the fan's own idea of "balance" or "making things more interesting", which rarely fit my own preferences.

So to sum up : does your patch ONLY tackle bugs and diplomacy, or does it also change other things in the game, like units' stat, treasures and the like ?

As far as I can tell from your short post, I very much share your view on modders and fan patches. I hold very little interest in modding and eternal twisting of unit stats. 1) The patch does *not* change any unit stat. One exception: the ship capacity (maximum for all transports). I did not find any other way to overcome a massive problem of MoM AI, who are unable to transport their units to other continents. I decided to allow this, because it is the lesser evil of the two. Other than that, NO changes to items, monsters, unit, spell effects...

2a) There are a few changes that were not present in the 1.31, but they were recognized as bugs based on the study of the big Prima Official standard guide and the Code itself. For instance, the patch makes a difference for items loot from Lairs. In 1.31, they were given randomly because of a bug. So you could get a massive artifact from a small Phantom Warrior lair and the game was more or less won by that point. That is impossible now. - Some players complained about the change and I can see their point (although I don't share their view). OSG explains the mechanics clearly. And they work now properly. You should see much more variety in items as well (another bug).

2b) There are also a few changes to things that hampered the variety in the game. Best example is the presence of Fire creatures in standard lairs. They were excluded because of a bug (confirmed from OSG). The game is a bit different, but in fact, it has more variety. It is the corrected original.

3) The game, however, plays differently. Mainly because of AI, who now uses its overwhelming advantage to much better effect. You have to play differently to win, perhaps. Somebody may find this annoying, because it used to be so easy to crush the hapless opponents. My advice is to play the game on simpler difficulty. Hard instead of Impossible (for veteran players). I do so as well, although winning on impossible is not... impossible. With some luck or good wizard configuration, no problem.

Ok, so I have to say : I love you, and I'm going to download this patch (is it the 1.40j from Realms Beyond ?) and start a game.
RIGHT NOW !

Trying to maintain peace with the AI wizards is like trying to maintain a relationship with a woman. They're going to ask you for this and that and still stab you in the back in the end. ;D

In basic MoM, there is at best a very narrow window between being so weak the AI feels like it can pick on you, and so strong the AI feels like it has to crush you in self-defense. This makes it incredibly difficult to maintain alliances with the AI wizards, or even to maintain a state of peace.

Each of you has one single, solitary goal: To conquer the world, control all the magic and oh yeah...Toss the rest inna tha void!