"I say invade, but invade small scale. Make some reformations, focus on counter-terrorism more, and get a load of boots on the ground with the sole goal to get the terrorists, and other than that, just shoot out of self-defense."
Look, I get what you're going at, but you have to think practically here. First off, let's assume a good scenario where the country allows American boots on the ground (which would still take a LOT of diplomatic work). You need people to build a base. Then you need people to guard said base. Then you need a logistics team. You need a supply line. You need people to protect said supply line. How are you going to conduct raids? By air? You need helicopters and crews. Then you need gunships to fly support. All this adds up, to the point where a single patriot missile battery requires 400 troops to man it.
http://news.yahoo.com/pentagon-send-missiles-400-troops-turkey-093600827.html
In Somalia in 1993 we tried the boots on the ground technique in raids, and it got a lot of men killed (granted, it was in a major city. I know I could have better examples). Task Force Ranger had 400 combat men, with additional support personnel. But they needed backup, which came in the form of the 10th Mountain Division, a Marine Expeditionary Unit and a bunch of Pakistani and Malaysian soldiers.
This is all, of course, assuming that the country allows our troops in. Which Pakistan will not.
So I get what you mean by "limited", but "limited" still would involve thousands of people. What you're going for I believe is "covert" which is much, much worse for PR than a drone strike. Case in point - the Bin Laden raid.