I admire the whole work You put into this map, it required both great mapmaking knowledge and a lot of time, but I must say that in my opinion, you didn't take the right direction :/
The interface is very unfriendly and definitely not comfortable. For a good skill picking system, look at this map:
Abyss Gates v1.3 - The Hive Workshop - A Warcraft III Modding Site
Also some beta version of next Heroes & Armies had a nice one, a whole tree that appeared on the screen, but I don't really remember the name, and there's a lot of fakes of that map.
For a good inventory system, look at this:
TKoK: Eastern Kingdom v2.02beta - Warcraft 3 Maps - EpicWar.com
Attribute picking is fine, though I'd rather have it as a shop, not those tabs. Here's another example. I'd recommend generally checking this map out, it get's boring, but there's a lot of great ideas in it that might inspire you.
Tomb of Jarahcon v0.95a beta - The Hive Workshop - A Warcraft III Modding Site
Rexxar's campaign is a good example of an enjoyable RPG campaign.
Terrain could use some more love, the caster model doesn't really fit, just a normal Blood Mage would be better, but that's my opinion.
And now what's flawed the most, imo. Gameplay is so plain. You just run around and kill creeps. For an RPG to be fun in wc3, you need to make some AI action and/or interesting quests, not just "kill and fetch item".
And finally. Why are you remaking a game in another game? It NEVER works. It would take a huge squad of top-notch mapmakers to make a wc3 Diablo map comparable to the original Diablo. And still, better solution would be to play the normal Diablo, than some wc3 clone.
To sum up. The quality is great, you showed some great skills in the mapmaking, but the result isn't enjoyable. It's just not fun to play, for me. If you continue mapmaking after finishing this, I hope you decide on making something more original and suiting the world of Warcraft 3
Pozdrowienia z Warszawy,
~Andriejj