Whoever needs your vote the most gets it. It depends on who is on your list, not the order of their placements.
I.e. I can't determine who needs my 2 votes? And also I don't know who got my 2 votes in the end?
Correct. The idea is that you shouldn't be worrying about that. Include people whose judgement you trust. The vote should reflect trust relationships and not be manipulated directly. I kinda wanted the same thing (fine-grained control of voting) earlier in the thread but now I'm thinking that's not that important. We'll see how it works in the next round.
I have 214 earned merits. Let's assume I have included 30 persons in my trust list. How will system choose my vote, I mean by which criteria, since I have capability of voting for 21 member. How someone from my 30 members will be excluded/included?