first, can one be granted asylum on the grounds of religious persecution? - this depends.
If you're claiming religious persecution from Jehovah's Witnesses, then I doubt it, although you may as well give it a try - I might do so if I were in your situation.
my plan is to leave and eventually leave the borg without my family knowing. So if I apply for asylum that would defeat the purpose - ok, then perhaps the best thing would be to apply for a job in the UK or other English-speaking country (or in another country such as France or Germany if you speak good French or German).
As an economic migrant what do I need to do? - I don't know. I'm not good on those kind of details. I'm a bit of an academic myself but I don't know shit, really. Sorry, buddy, you'll have to ask someone else. XD
What BSc do you have? What experience do you have?
If you have a first class or upper 2:1, have you thought about doing a PhD overseas, e.g. in the UK?
With UK-born PhD students, you get funding that covers all your living expenses, etc. I'm not sure if that's the same for foreign-born PhD students so you'll have to look into that yourself.