I dont think she loses the intention or is prudish. I think she spoke in a humble, confused, and idealistic way. Which is the way we all are when were young and experiencing true love for the first time. (or at least what we interpret as true love)
"...everything modern is instantly dated..." THAT old chestnut. Macbeth and Julius Caesar are just two examples of plays Shakespeare wrote about historical settings (medieval Scotland and ancient Rome) which predated his theatre. Both were written in his own contemporary English and both were almost certainly staged in a variation on doublet and hose - contemporary dress to him. I'm not in favour of messing with the poetry too much but Shakespeare himself was bitingly modern - so get over it!
You are losing the intention. "Take all myself!" is a big statement! She is a virgin and saying that she will give herself to Romeo! There should be more excitment!
Accent is irrelevant. Execution is very impressive, though wouldn't Juliet wear her sexuality on her sleeve a little more? Or is this rather prudish interpretation a more accurate representation of a girl who was probably 13/14yrs old ("Two more summers wither in their pride ere she be ripe to be a bride")? Well acted and well spoken, if not particularly 'sexy'!