Maps:
There will be more maps. As said, the engine supports maps many times the size of the current map used. I think they just gave us a basic little map to use in Beta 1 as part of the whole "dumbing it down" thing. The map itself is not actually bad, its just smaller than DotA's one map. Demigod, however, will have more than one map, which lets them have smaller maps without sacrificing the epic option of larger maps.
Heroes:
I think they might be a little strong, but its not a huge issue. Once we get the ability to enhance creeps one way or another, it should be less of a problem.
Items:
Recipes are bad. They are extremely difficult to figure out (which turns away new players) and imo they actually decrease the possible options for the late game. There are a lot of different recipes, but in reality, most heroes only have one or two viable options to work toward.
Innociv posted an item upgrade system in the suggestions board, and I think that is the best way to do it. It reduces the initial confusion by actually decreasing the amount of items, yet at the same time provides a straightforward way to make items gain power as the game progresses. You still have to plan in advance as different items will allow for different boosts later on, but the initial options are more user friendly. Since the boosts would naturally reflect the base stats of the item (at least to an extent), you don't really have to research to prepare for the late game. This makes it easy to pick up, while still leaving advanced item paths for people who bother studying these things. It also results in a huge amount of late game item variety, as you start with one of a few basic items and customize it for the late game, instead of buying a specific stat boosting early item and turning it into one of a few specific late game items.
Please, no recipes.
Healing potions need a cooldown. Its already very annoying when someone stops for a second and regains all their health, the last thing we need is for them to be able to do it as often as they want. It would quickly turn the game into a battle of whoever has the most potions.
Gold:
Gold mines will be on most maps. This will solve most of your problems.
As for last hitting and denying... Well, earlier in your post you talked about how Demigod is looking like a twitch fest. Yet, when you think about it, DotA is a huge twitch fest as it requires you to always manually retarget to different creeps so you can beat our your teammates and steal their kills. Then you turn around and get the last hit on your own creeps so enemy Heroes don't get the exp. You call Demigod a twitch fest?
Last hitting and denying are compleatly unnecessary. I don't think either truely adds to the game. In fact, I think it detracts from the game by building unnecessary hostility between team members. (There's enough kill stealing in FPS's, the last thing we need is for it to start spilling over into other generas, and worse, encourage it.) Plus, this discourages team based anti-creep attacks. If they ever make creeps stronger, then last hitting will discourage team based combos designed to quickly take out a wave. If they don't make creeps stronger, then all the exp goes to the first guy who casts some kind of AoE spell. Its a no-win situation.
Leveling:
I don't really see the problem. You get the first few levels fast, which is nice as it lets you unlock a few basic abilities. Once you get past the first few levels though, leveling is actually pretty slow. I think it works.
Also, you make it sound like standing in the field farming creeps without getting smited is easy. Against real people, its not such an easy task. I think this is mostly an issue about the specific map. Other maps will have strategic points which will greatly affect the flow of the game. Even in the map we have, losing the middle flag in the late game or losing a portal at any time will result in your quick demise. Losing a portal cuts your creeps in half (and lets enemy creeps walk straight into your base past most of your defenses), while holding the war idol late game almost doubles the amount of units you have on the field. There's a bit more to it than "get to level 15, walk in, win." You again have to remember that real people will also be at level 15...
Your Final Notes:
You are asking for a DotA clone. If this was an FPS, then would you want a Halo clone? If you think about it, Halo was a very successful game. Why doesn't everybody just copy Halo because we know that exact formula works? (Yes I know Halo wasn't the first, I'm just picking an example here.) What if every RTS was exactly like Tiberium Dawn? We don't want a DotA clone. DotA was the first of its kind, but it won't be the last. If we stopped at the Pong formula, we would have missed out on tons of stuff.