1. I have No Idea what you mean. Do you want an InDesign script "target" illustrator? Try Brigdetalk.
3. No amount of scripting will make #3 possible. [*] If you "desperately" need this, write a plugin for it.
4. I'm not sure, but as far as I know nothing special is needed for that. At least, not if your own script shares the same engine. If it doesn't, then there is no way because that's how it is supposed to work, and no amount of scripting can work around that.
For the second question, i could nt find it in the tool guide. Could you please help me to find it out.
For the 1st: not with InDesign scripting, you don't. Look at Bridgetalk.