yeah the frozen statue thing kind of isn't them at all, the voltari are over 5k years old and still moving around quite a bit, and while they are not as as strong as new borns they don't ever get as weak as that. the new born strength is fueled by there own human blood.
i would keep everything at the supernatural strength and speed, rather then try to figure out a specific catch for physical immunity I would give them mythic toughness, no catches if the ability normally requires, but assume any attack or power that gets by it does whatever damage it can do against armor 3, i would give them inhuman recovery to help speed the healing process. If you even wanted to simulate the newborn strength I would keep everything at supernatural and just add some extra bonus to the benefits of supernatural strength a high bonus on grappling. Its such a tiny period of their existence that i wouldn't build the template around it. Newborns cannot use any fighting skill whatsoever, they simply do not have the control for it, so make all their weapons and fist skills mediocre for the duration of the new born phase. established vampires don't have issues killing them, they just don't want to be grabbed by them. In the southern wars they made armys of them(10-20 at time) and used over whelming numbers to kill established covens. Remember established covens don't number over 3 in the norm, 4-5 would be the most and only in wartime for self protection. Even when the invaders did this most of the new borns ended up dead.
They can be hurt if hit hard enough by say other vampires and a were creatures teeth can cut the skin and a wizard should be able to use spirit(force), well enough to bypass the mythic toughness. Once you exceed their stress and consequence simply declare that they have been broken into a few moving pieces that are trying to reassemble themselves. now you burn them with any type of fire doesn't have to be munch a lighter should do and boom dead vamp.
If you don't have the mojo to kill them quick enough any effect that will suspend them in mid air should give you enough time to escape. Without leverage no amount of strength is impressive.
as for their other powers something for the senses, the venom should have two effects, if you get bitten it uses pain to paralyze, those of enough will or enough fate points might be able to throw it off but that should be checked every few passes. The side effect though is in 2-3 days you become a vampire of the same make. There is no cure if the venom isn't dealt with before it spreads to far. Most do not have abilities beyond this. Those that do are rare. When they do have abilities the largest group are mental and emotional controls or defenses. Very few powers extend to the physical. Also once turned they do not change.
They are set for eternity.
This can mean a lot depending on how you want to play it. Can they improve skills or are they stuck where they are forever. If they do not already know something can they learn to do it. For balance I would have to say no, especially to learning any type of magic. Skills could be put on a huge learning curve. In the books the biggest thing to change a vampire was love, with that they could become or learn something needed to make it possible and once they love they never stop. (it was a romance story after all)
Vampires enter a feeding frenzy when they taste human blood so its difficult for them to make other vamps, they normally just eat the dude they bite. Carlyle was the only one who didn't have this issue and Edward and alice could avoid it for Bella only. Every other vampire simply hoped they could stop before they killed the person they wanted to change. This is why there aren't many vamps of this type, they simply cant not kill something they bite and their victims simply don't have any ability to escape them whether bitten once or not. a roll to avoid blood lust and a fairly high one at that. They also get this way with spilled blood even tiny amounts but the roll is a bit easier. This includes well fed vamps so it is a very debilitating drawback. It makes it difficult for them to be in the presence of humans if they haven't fed recently. And as long as they don't taste it even if they fail the blood lust roll they can hold it in check long enough to stalk the victim to somewhere safe to eat. This should be played up as its the main reason these vamps dont go near humans and generally only associate with other vamps
This is also the misconception of critics of the story that say Edward was a stalker and Bella a willing abusey (sic). Edward was constantly fighting they vampiric urge to kill her and the moral urge to love her. Myers has written a book called midnight sun which is a retelling of book one from Edwards perspective. This book is much better at explaining the nature of Myers vampires and their way of life. She keeps it on line and its only 183 pages. She does not intend to finish it?
But as a a resource and explanation of her vampires its very good. Her site also contains other short blurbs about them that proved very helpful.
A wizard would probably lose the ability to use magic for at least the first year, he wouldn't have the control needed to use it. Could u imagine a member of the white council who was also this kind of vampire.
I didn't mean for this to be so long