I'm afraid that, other than maybe the occasional polishing of To the Bitter End, I don't see myself doing a lot of Warcraft III stuff in the future - I've got quite a few other projects in the works that I'd rather be working on.
As for spells for a Blood Elf Warden model, there are a lot of considerations for this. If this is for a multiplayer map, be sure that the spells remain balanced - as proud as you might be of your creation, it's no fun if it breaks the whole game. If it's single-player, the abilities can be as powerful as you like, as long as he ends up facing enemies powerful enough to still pose a challenge.
In terms of what actual abilities to create, decide on what sort of character he is and what sort of tactics he's likely to use. He's an elf, so he's probably agile - think of skills that involve precision, speed and agility. He's a Blood Elf, so he craves magic - he should probably have abilities to sap, eat, or absorb magic from enemies, and maybe he's magic resistant. He can probably use some magic himself. Maybe give him abilities similar to the Undead Destroyer, where he can 'eat' magic so that he can use powerful spells against his enemies, but his mana drains over time? Is he heroic, an anti-hero, or villanous? A hero tends to have protective, strengthening, or healing spells. A hero might use direct attack spells, but a villan would use spells that not only attack, but also cause as much pain and suffering as possible - even their defensive spells might have a twist that makes them cause harm to others.