[capnq]

3. What are teh keys to econ development? In Stars!, if you didn't manage your population properly, you were screwed compared to those who understood the 25/33% pop breakpoints and how to use them. Is there anything similar to that in SE?

There are a series of breakpoints listed in Data\Settings.txt ("Pop Modifier" entries). In the unmodded game, the breakpoints are at 100M, 500M, 1000M, 2000M, 3000M, etc. Some mods add much finer graduation to the bonuses.

I am very annoyed that I bought and payed for SE IV only to find out that I didn't actually purchase the latest Version of the game, and there is no upgrade path.

I'm surprised that you found a non-Gold copy available for sale; SE IV Gold came out nearly a year ago.

If you are going to want to play multiplayer on PBW(which you should!), you will want SE4 Gold.

PBW also supports the final non-Gold patch (v1.49) as well as Gold. It's a bit harder to find opponents for "classic" games, but not impossible.