1. You can briefly control your target's movements if you're creative enough with how you do it. Though since this isn't a strong technique, you can't just control people however you want. Basically what I like to do is misguide them, using the threads to try and guide a punch or something to slightly miss me or not hit a vital area if you can help it. Another thing I like doing is momentarily binding someone's hands in the middle of a hand seal, allowing you to do something in return. It's all about creativity.
Though a strong enough puppet user can control weaker people, there's another technique for it which isn't on here so we use this one. Sasori was able to control some members of the Surprise Assault Squad Kankuro led in the Ninja War, but don't rely on that.
2. No, you can't use this like a rope. Remember that this is only chakra designed to manipulate puppets and other objects like tools and so on. Meaning that it's not that strong and can't simply be used like a rope. If you wanted to pull something towards you, that would be possible but nothing like a rope. I have a custom technique which allows you to do that though, which if you stick it out with puppets, I might consider teaching it to you.
3. Yes you can, and while you can control weapons like that, remember that it's not a wall. Connecting the string to th weapon won't make it stop, you'd have to misguide it or manipulate it to hit something else. Think of the style of puppetry we use: marionette. The string stays the same length to the puppet, and it's only by moving the string will it move whatever it's connected to. Except we have an advantage of being able to control the length of our threads, a rather convenience if I say so myself.
4. You're right, you can't use these to direct fireballs or other such projectiles. What you have to remember is that the threads are comprised of a weak chakra, so you can't really do much about techniques like fireballs. If you're skilled enough, you can use this against Earth based techniques due to their solidity (so not stuff like swamp). Just not fireballs since it would eat the chakra basically and you wouldn't be able to use it.
5. While this is effective in theory, one of the rules we spoke about earlier mentions this about not being allowed to use shadow clones. So you wouldn't be able to create chakra threads with a clone's orders or anything. The most you could do is form a Rock Clone or something similar to hold you up while you do other things.
While it's all nice and dandy, there's a lot more you can do with threads. For example, if you're in a forest environment and you're in hiding from someone who has no idea where you are, you could use this technique to pull on leaves, rustling them to generate noise of a false location. You can also use it to levitate kunai off the ground, like Chiyo has displayed, or even redirect your own weapon attacks after they've been thrown.
The possibilities are endless!
If you don't have any questions, we'll move onto the next stage.