If you put a limit order in for 5.00, most of the time it'll hit at
5.00, but as an FYI...these shares are flying so fast, it could buy at
some price very close like 4.99 or 5.01 or something like that and
with the other half of your question, as long as you have "All or
Nothing" with your order, you will not buy unless you can fill the
complete order..

Hope that helps...