Actually Kotor is pretty good on its own. Kotor2 however is a quite different story.

The game launcher shows this. Does that mean I need to toggle on all the other files first to activate the DLCs and the patch?

You want everything checkmarked.

How are the DLCs tied into the game? Would it also work to first play the main game and then activate and play the DLCs if I'm still up for more or should they be activated as early as possible? I took a quick look at the DLCs' contents and some don't sound like they'd fit too well with the way I experience the game right now (alien spaceship, chinese invaders in Alaska etc.), more like a bit of fanservice for those who are already done with the main game.

I'm not saying that they don't make sense, just questioning whether it would make sense for the main character to engage in these missions during the regular game or whether it would somehow ruin the current atmosphere (exploring the limited area around Washington on foot, as a Lone Wanderer, as opposed to joining the army in Alaska; and dealing with enough post-apocalyptic weirdness already without adding aliens). If they add good perks, that might be an incentive to activate them early though.

They do add some good perks and i'd recommend to do Anchorage somwhere at level 10. Leave Mothership Zeta for the late game and make The Pitt and Point Lookout at around level 20-25. Broken Steel is meant to be played after the main game ends, as it will serve as an epilogue/closure.

That's very helpful, thanks!

Operation anchorage breaks the game. The rewards are ridiculously overpowered. Seriously try losing with the stealth suit.

And you're not in Alaska your in a simulation of Alaska the other way would make no sense.

hedwards is right about being in a simulation. A simulation that recreates part of the the events leading to the apocalyptic wastelands. Yes, the rewards are ridiculous. You can always choose to use them or not.

And.. because it's a simulation - doesn't that mean (IIRC) that you can go do it even at level 1? No need to wait until L10 or so - because as a simulation - everyone that 'enters' it is 'the same' as anyone else when they do - no matter what 'level' they are outside the sim.

Or, maybe my memory is foggy..

Most of the Fallout 3 DLC's can be done to any level (except Broken Steel). Anchorage is the easiest one for early levels.

Anchorage is definitely the easiest dlc. It is also the least interesting, but you do get some cool loot! I would definitely do it before you even think about The Pitt. Point Lookout was quite challenging (but very fun) if my memory is accurate.

Point Lookout was a winner. I didn't find it hard though, most of the game was somewhat easy to be honest. Unlike the original.

How did you decorate your apartment? Mine was Pre-War

I literally filled it with severed heads... literally. :D