People like to say aliens wouldn't look like us, and that makes some sense intially, because human form isn't really too efficent. But we evolved this way for a reason, and in the absence of comparison, there's really no reason not to assume aliens would look like us either.
Yes, human form is vunerable and inefficent. But what you must understand is that we have come as far as we have because we are not very well adapted physically to our environment. We had to manufacture the adaptions, we had to be smart to do that. If you don't believe me, look at the dolphins. They may very well be just as smart as we are, but they are so well-adapted to their environment they didn't to make tools and build buildings or anything else.
So I would expect an alien race to be rather like us. They're not really well-adapted to their home environment, but they do have the means to manipulate it (hands or something like them).
Regarding speed: considering the number of times you see planetary bodies about and they're not moving away from you at tremendous velocities, speed is almost certainly relative. to the largest object nearby in an interplanetary sense.
Regarding AIs: The real problem with such a system would be in the IFF. AIs don't do nonlinear thinking nearly as well as people, so they can be much more easily tricked or trapped. You don't even have to hack the AIs, just present them with IFF coding that says you're friendly and perhaps a visual mod mockup to make it look so too. They'll probably be programmed to return fire if fired upon, but even so, you'll do a lot of damage before they get the chance to do some back.
