Things shouldn't be changed to be not like DotA just for the sake of being different than DotA. Many of the things in dota are in there for a reason. Why should it be arbitrarily different than DotA? Should fun be sacrificed just to make it different? As an example, look at WoW. It was basically an EQ2 clone, except done right, and now it's a runaway hit.
You seem to hate DotA, and say it shouldn't be like DotA because that's not the kind of game you want. But that's just the thing! Not everyone wants the same kind of game as you do. I want it to be like DotA where it matters: Balanced, fun gameplay. And DotA has had a lot of time to refine the gameplay. Why try to rewrite a known formula? This will be only the second game of its kind. Trying to completely rewrite what kind of game it is will only result in a weak, unfinished game (See: SupCom).
Some counters to your main points:
-There's a reason heroes in DotA don't start out much stronger than the creeps: the creeps actually pose a threat, and aren't just food. If you go alone against an army, you shouldn't come out winning. Also, you'll get the satisfaction of power progression after you become powerful enough to destroy armies. Additionally, stronger creeps means it's actually possible to do a push. Right now, a single demigod can stop a huge army of creeps with a single spell. This makes pushing somewhat pointless.
-Games that run shorter or longer than DotA games are not necissarily bad, but the game length shouldn't be changed just to be different. Dota games rarely last longer than an hour, and even fewer games past that length. Many games are decided by half hour games, but longer games can truly become epic, and almost always ending before 1.5 hours.
-There are a few reasons for the item recipe system. One, you aren't just selling old items to get "upgrades", but actually upgrading and working towards a specific high-tiered item. Also, you don't spend all game saving up for a single item, but can get the parts and start seeing some benefit sooner. I like how demigod's items aren't just "+x stats" but actuall have effects (like dota). Whether they can get a good item system in without recipes remains to be seen.
-A broad understanding of the battles flow is also very essential in DotA. It's not just micromanaging a hero to kill another hero in 1v1 combat. You have to keep track of where the other enemy heroes are to avoid ganks, and keep track of which lanes are being pushed as well. You have to communicate with your teammates and know when to push and when to back out. It takes less micromanaging than regular RTS's IMO, and more smart management.
Some things with which I agree with you:
-I also don't really like the starting 10 minutes before most action starts that is in DotA. It serves a purpose, but it would be nice to see it removed in Demigod if possible.
-I also thing last hitting and denying should be mostly removed. I'm not so sure about last hitting though, but definitely denying your own creeps.
There are a lot of changes in Demigod that are different from DotA. Generals create an entire new subset of gameplay. A new game engine allows more flexibility for spells. A single Assassin Demigod has a lot more abilities than DotA heroes do. Strategic Zoom adds a new way of seeing the battlefield. There's probably more things we have yet to see, as well.
On a final note, I'm not saying Demigod should copy DotA verbatim. I'm just saying things shouldn't be changed arbitrarily, but for a reason. There should be a reason to make a new item system, a reason to change the basic gameplay, a reason, other than just being different, to having weaker creeps. Difference does not automatically make it better.