I saw that it was possible to build bases, I guess I was just being paranoid about how long I would have to do so. If it was as tight as 10 minutes with two heavy oxygen tanks, I think people would be complaining about that instead of recommending the mod. I've downloaded Galacticraft and the Galacticraft Planets addon (and of course the Micdoodle Core).
I've gone ahead and downloaded Rei's minimap for now, but I'm still hoping for more details to help me decide between Project-E and some of the competing mods, and it's less important when I'm using GregTech to get worldgen iridium ore, but I'm still curious about the best way to get iridium ore using only IC2exp (I know I have to find some in a dungeon chest first, but after that would it be easier/faster to look for more dungeon chests or to scan it and use a mass fabricator and replicator?).
Side note: the apartment complex where I live will be shutting down the telecommunications for maintenance in a little under an hour (and possibly keeping them down for up to 7 hours ), so I won't be able to respond to other suggestions or questions until after that. I plan to do some other things in the meantime, but if I get too tired or (unlikely) run out of other things to do, I might start an offline game with just the mods I've downloaded so far, instead of waiting for more suggestions.