If I use Double Spell to use my opponents Premature Burial, thus bringing out Vampire Lord and later the Premature Burial gets destroyed by MST, Heavy Storm, ETC, will Vampire Lord be special Summoned by his effect, since it would have been destroyed by your opponents Premature Burial?

Please ignore this idiotic question since I just realized that on the card itself it says that the selected Spell card gets activated as your own spell card.

Good catch! That's what makes Vampire Lord a little more of a risky play than "Scared Phoenix" (yes, I said "scared", since no one really uses him anymore).