Space strategy roll-call!

[Martok]

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Thank you Martok-sama, I'm in your debt.
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You're welcome, Mouza. I hope at least one of those will be to your liking.

Note: I forgot to add MOO2 to my above recommendations. It's not my personal cup of tea, but it remains among the more popular space strategy titles out there.

What's the speed/pacing of GalCiv2? How long does it take to get through a turn, how long does a campaign take, etc?

I think I need a game I can play for 2-3 hours at a time without getting too sucked in, and the 3am MTW sessions are starting to annoy my better half.

Heh.

Fortunately, you can set up games for any length of time. You can play a Tiny map (which I think has around 15-20 stars) in a single evening, all the way up to playing an Immense map (which can have over 1000) for weeks/months on end. Also, you can set the research rate to fast, normal, or slow.

What depth of micromanagement needs to be used for planetary admin?

As much or as little as you like, really. While it's obviously often a good idea to give your home planet (along with your first few colonies) some extra personal attention in the early phase of the game, it's not that necessary overall. You can line up as many buildings in a planet's build queue as you like (within the limits of the colony's usable build tiles), and then just forget about them until they're done -- you'll automatically receive a message when a planet's build queue is empty. (You're also automatically notified when a new ship is built.) Colonies will also automatically upgrade any buildings once you research/acquire the requisite technology -- e.g., turn Basic Factories into Advanced Factories, Terraform previously-unusable build tiles once you research the Terraforming technology, etc.

The only real problem is when you're playing on larger maps, as you can have dozens or even hundreds of worlds in your empire. Fortunately, a soon-to-be released free update (called 2.0) will be adding planetary governors to help streamline things for you (see here for more). One minor caveat: You do need both expansion packs to best benefit from this update (most of the improvements require Twilight of the Arnor).

Can you configure the game for different sizes and densities, and are maps randomized?

Yes -- to both parts of your question.

You can choose whatever settings you like for just about every option you can think of, star density, planetary density, etc. Alternatively, you can everything to "random" and let the game surprise you. As a third option, you can also set some options to "random" while setting others to your specific taste. It's really all up to you.