Omg, reclaiming of Syberia and Alaska was done by Russian Empire, not Soviet Union. And sale of Alaska was mistake, what show geological discoveries in Alaska later...
As for me, I never give full control to AI. I prefer total manual. In most of my games I found, that controlling empire in galaxy with 700 stars is still possible (yes, I like a lot of micromanagement).
For my opinion expansion in DW must be limited only number of available planets, cash for colonizers/availability colonists, distance to enemies/competitors, etc. This factors also useful, when we take for example human history. If you read about expanding some empires by colonizing you may find, that their colonization was only limited by available territory/distance to colonies of other empires. By the way, main reason is that Crimea war began against French/Great Britain, why Alaska was sold. Russians had decided to sale Alaska, because there was threat, that GB troops in Canada could easily conquest it.
But never mind, sorry for small lecture of Russian history.
I sure, that main limitation of expansion should be high costs for development of new colonies like sots. Take a look for this game, this gameplay element fits perfectly for DW colonize concept.
< Message edited by WiZz -- 2/12/2012 9:43:52 PM >