Confused about wand rules (plus Lee rocks!)

[prep0strus]

No: HPFGUIDX 172306

Thought the book was good, aside from the slow camping period, but I
am confused about some of the new rules regarding wands.

So, a wand (specifically the elder wand) can change mastery if you a)
slice the owner's throat while they're sleeping, or b) defeat the
owner in battle, even if you defeat them with a simple expelliarmus
spell and they're not even using the wand?  That's what I get from
draco getting control of the wand from dumbledore, and then harry
getting it from draco.  But the part I have a difficult time with
is... why didn't voldemorte gain control when he 'killed' harry?  I
think that was as much a defeat as draco gave dumbledore and harry
gave draco, if not more.

And I'm also confused about the parts of harry and voldemorte which
were in each other, and who would die at what point... but I imagine
that will be discussed a lot. (But, if dumbledore's plan had gone
appropriately, and Snape was the elder wand's master... would harry
have died in that final battle, with voldemorte living? cause that
don't seem right)

I also didn't like Dumbledore knowing to give ron his gift - i do
think it shows a lack of faith in ron, plus an unnatural ability to
see into the future.  plus, i hated that whole plot point (we've been
over the jealousy and lack of faith in all the previous books) and i
think the book would've been stronger and tighter without it.

Finally, YEAH LEE JORDAN!!!!  Man, I called it... I was so bitter he
wasn't in book 6, I said everywhere how i felt he should have a radio
show that spoke the truth the ministry didn't want the world to know,
and i'm sure that's not unique, so i'm sure jkr came up with it
herself... except she didn't - she totally stole it from me, and i'm
awesome! :)

ok. more than enough for now.  thanks for anybody's help with the wand
rules confusion.