Well, of course we want more - we're gamers, you can never satisfy us

However, most of your ideas have already been covered before and have been addressed.
The maps are made in 3DSM, not an in-house tool set - like World Editor for Warcraft and Starcraft games. The locations of the towers, the health crystal and the creep lines are all controlled via additional files that add these things onto the maps. In fact, I believe one such forum goer has already created his own modified creep lines on Cataract by editing these files.

We're receiving two new Demigods for free, however after that they may be released as paid content per Demigod as unlike DotA or such, the models for the Demigods are fairly complicated. Again, several people have already taken steps to creating their own Demigods - in fact, I've seen a SPORE game model being used in Demigod, so we're well on our way.

With 1.2 we'll see the offical mod support we need to begin rolling out new content on our own, and as always there's going to be good and there is going to be bad. Over time, it will self sort based on the community's reactions to it, and I expect we'll see things like community map packs or Demigod additions that are balanced and creative.

I don't think Stardock are going to be releasing copies of 3DSM - even stripped down versions -  mostly for legal reasons. What we're most likely to see are plugins, addons and a patch released that allow us to use our own versions of 3DSM to interact with the models and save in the file format needed for Demigod to use them correctly, as well as some kind of basic documentation. The problem with how Demigod was created was that it really wasn't created with large scale modding in mind - it's kind of an after thought that has been given priority based on the communities reactions to the content Demigod has already; basically, we're asking for more than is realistically financially possible from GPG or SD so they're giving us the tools so that the dedicated or educated can make the content for the rest of the community free of charge.

As for the balance concerns; being as a modded Demigod would need to exist on all people's computers for the game to launch successfully, what we'll see is people not using particular Demigods if they're not balanced to the liking of the community. The well balanced and designed ones will be very popular - you won't join a game where some guy has made himself a Demigod that passively deals 1,000,000 mitigated points of damage in a aura with a radius the size of Snipes Range, because you'd have to download it and put it into your game first. Obviously, the community would reject such a clearly unbalanced and unfun Demigod. As with SPORE, the popularity of content basically self-sorts it out. The smaller the amount of content - which is generated by a smaller community like ours - the easier it is to sort out the trash from the good.