I'm good with questions because the point of the descriptions of the techniques is to be clear for everyone to understand them. So no point in simply repeating the description, but instead asking questions you're not sure about and I'll try my best to reply to them. But, who am I to stop you from writing descriptions. If you enjoy them, or want to post them for RP sake then feel free to.
1) The part where it says create a body of water to block incoming attacks is pretty clear, if you ask me. So yeah, you can surround yourself with it. It's pretty much a technique to create a water source and then derive other techniques from it.
2) Well, you use your chakra so if a sensory nin can sense your chakra, I doubt you would be hidden from him. What they meant with hide your presence would be more like visually, but that still wouldn't effect dojutsu because they can see chakra as well.
3) Yes, I think you could. Wiki says that it's a continuous stream of water so we can safely assume that you can keep it for a few seconds. In those few seconds, if you apply realism, you could spin, run, move, jump or whatever and it would realistically effect the water stream. To give you and idea how the technique looks like, here is the picture. Any more questions?
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