Unfortunately, on 24-player servers, getting a 2nd hive or a shift is more or less mandatory first, for eggs...
I like shade first or third hive, usually second is kinda fail, because it doesn't help all that much in the mid-game when the marine buildings are already in place. If you go shade first you more or less MUST go crag hive second, unless you're absolutely sure you can get a 3rd hive. Oni and fades without carapace are an epic fail against marines who know how to play and shoot :-D .
If you go shift first, it can help greatly to put the shift in some central location (like hub on ns2_tram), and it can pay off immensely. However, it can also backfire if your team is bad and they lose the shift and the eggs around it, leaving you with nothing. Shifts are also fragile, so keeping them hidden or having a gorge with hydras around them is nice.
Other than that, just get stuff and win
. I find chamber upgrades to be generally less of a priority than hive upgrades, depending on things. I mean, carapace and celerity are always useful from the very start of the game, but everything else can be delayed until leap, bile, spores, and blink are up or researching.
Bone walls help escaping oni or gorges survive so that can be nice :-D . Drifters are situationally good (less good in a 12-player game though) for vision and the occasional troll enzyme.
Generally, alien com is a bit easier to play: time your upgrades and expand everywhere where marines are not.
Oh, and yes, base rushes are extremely powerful on alien side, but if you want to keep them a secret, the team has to have PERFECT discipline (i.e. go somewhere quietly, hide until all or most of the marines leave, and then rush), and you gotta find and kill the obs first before the beacon goes off. So they don't guarantee a win, but they can be extremely powerful, especially early game, and can cripple a marine team to the point of not being able to come back (if they're bad enough) in the first 2-3 minutes.
P.S. It's also Kharaa, not Kharra
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