I think.....just the same meaning tho :) ok waiting for guru help you for this question so I'll got mine hahhaa

How far are you going to take this? - This is used when something is escalating. How long are you going to keep this up? - probably a non escalating annoying activity. How long are you going to keep this going? - Not an annoying activity as far as we can tell. May or may not be escalating.

I would say that they could all be used in similar ways. But the first sentence implies that the situation / behaviour is changing, developing (becoming more extreme?), whereas this is not necessarily the case with the other two, where it may be just repetition or continuation of what has already happened.

Yes. They all sound the same to me.

it seems they are all same. maybe you can put down some context for each sentence here?