Hello Martinus,
I've been reading your ideas and I decided I should share with my thoughts on gameplay systems. I am aware that your goal is to make it as realistic as it can be, so here I go. One thing to have in mind - when we observe humans as a species (irl ofc), we aren't the strongest beings on the planet, but we adapt. And that I think should be a theme of empowering your character - adapting it to fight with a certain type of enemies.
Armor and clothing - Any kind of gear should only be crafted by a player crafters (no mob drops). Crafted gear would be without any stats other than armor and durability. The more armor you have, the heavier should it be, limiting your movement and attack speed. Losing durability of armor should result in increasing damage taken. That armor would need to be then enchanted.
Enchantments - There would be few types of enchants. For now let's limit to two types and call them general and situational ones. General enchants would have no limit of application - the more you have the better, however weakening the material, situational ones would override themselves - you apply them only . General enchants would be basically what gear in WoW is (primary stat), situational would work in similar manner flasks work, except there's no time limit (e.g. reducing damage taken by one type of physical damage).
Combat - Casters and rangers should be able to attack during movement, but there has to be a penalty. Something like decreasing accuracy, increasing casting time or energy needed for the spell/ability.
Mobs should always physaclly attack the nearest target - no taunting, no going to the caster because of aggro. DPS should stay behind target, to avoid taking damage. [f you plan on creating boss encounters]
Non-combat activities on a hostile ground - There should be a map, you could look at it in the city or buy it from an NPC. Every race should have different map (mostly name differences). Reading it, as well as eating or drinking should make player take more damage - less awareness makes it harder to take action.
Travelling - Mounts. Let's say you want a horse... You could rent it, but man, should it cost much. And it wouldn't always be a good idea - sometimes limiting your movement, endangering you.
Zeppelins. There shouldn't be routes as they exists nowadays. But we know from WC3 there were many Goblin outposts (gameplay reasons back then, but hey
).
A note: RPGs always tried to mimic rules of this world. Back when people could only use dice and paper, the system would have to be easy (calculation issues, resources). There's nothing wrong with simplicity, hell, the simpler the better. People like to feel stronger, better, more experienced and ultimately win. This is nothing worth achieving in the age of internet, since we have all the time in the world (physical games were really time consuming). Where levels fall into the category of failed systems IMO, skills do not. Skills in WoW were really clanky since all it varied was I guess miss chance. I think it should influence damage done, damage taken etc.
I propose creating a model which mimics not only physical world, but mental and spiritual. Since every fantasy takes inspiration from philosophy and spirituality, there are no exceptions, I think it's for the best to use some of the formulas you can find in there
.
Cheers mate. Also, if I can help in any way, let me know.
PS: Why stick with WoW engine? Isn't there any open-source multiplayer platform to use?