Hello I played your map and here is my review;
-So many starting items not good I think.
-So many item shops. It very confusing for newbie. You need to add Guide
-Mid lane better for leveling cuz other lanes are hard at begining
-Mid lane towers invulrable Minions going to die. It's pointless I think
-Terrain looks empty you need fill them with using some doodads trees etc.
-Towers attack heroes instantly.
-Heroes builded well but many heroes have out-class abilities. Varian have paladin spell divine storm. It kills class fantasies
+Spells based on stats very good. Your hero spells not become useless on end game
-Some hero builds force players to go neutral lanes. For example: Illdan needs to kill neutral leaders etc.
-Naga and Demon forces movement speed to high. Sometimes you cant escape from them
+I love idea upgrading your base by using salvage points. Its very unique.
-AI dont have any movement. They just purchase hero.
-Alliance southern lane attacks neutral creeps when sun rises.
-I try to wear Another class item it drops instantly and not refund price.
Salvage drops only hero kills. You can add bounty system to give salvage instant to hero.
Overall its enjoyable. You designed classes very well. Suggestions: Improve terrain, Decrease tree sizes, Make guide for items or make vendor for main items, Decrease neutral creep stats on begining. I bought many stat books at the begining cuz My team level not enough to buy some items. You can add basic AI to push lane etc. Add optional quest for midlane.
I rated your 4/5 cuz I saw potential on map. You can improve it better.