I have experienced most of the issues that he original poster lists; if he wasn't a beta tester, Stardock should consider making him a tester for their next release.
As an owner of the GalCiv 2 series, I am confident that Stardock will continue to work hard to fix and improve the game with patches and updates well after the initial release.
That being said, I think I share what appears to be the greatest concern from the original post: too much of the process of learning the game is left to trial and error. As an experienced TBS player, the learning curve hasn't been too rough because, in a manner of speaking, I already "know what to look for". The mechanics of Elemental do not stray far from the conventions of the genre, but like any game with this level of complexity, a working knowledge of those mechanics is essential, as is having access to something that will provide detailed information regarding those mechanics.
In this respect, Elemental is lacking, so much so that I believe some people will simply give up on the game. Even without referencing the excellent knowledge-base tools of other games from other developers, Elemental's documentation pales in comparison to one of Stardock's own products, Galactic Civlizations 2.
On another note--and it really hurts me to say this--the campaign is really quite poor. I'm sure some people worked really hard on it with the hope that someone would enjoy it, but it's very linear and bland, nothing more than a string of consecutive and very simple missions leading up to a very anti-climactic battle. The campaign uses so very few of the options available in the sandbox mode that it might as well be a different game. There's no need to make any improvements to your cities, save for the purpose building units; your cities never come under attack; and you only need to maintain a single army controlled by your hero tho travel from Point A to Point B to engage in all-too-easy battles. The campaign even tries to force you to split your units into two armies for a two-pronged approach leading up to the final battle, but it's completely unnecessary, as evidenced by that fact that I did NOT do this and was still able to successfully complete the campaign.
All told, I still think Stardock has a good game on their hands, and I expect that it will continue to improve. Forget about playing the campaign; playing a few quick games against the AI so that you can figure how the game works would be a better way to spend your time.