[Arya]

Just finished 7 ep.

Spoiler for speculations:

Actually I agree that the timing for Charlotte is a bit odd. Plus Silvya have had no development at all until now. But if I've understood right, the anonymous mail message said something like "ur lover will be the next" and teppei didn't seem to be so confused about who, even if images showed each girl.
If I had to guess I'd say that teppei'll rescue Charlotte, but for political matters the engagement between Charl and the blond guy could not be broken (it is something like roman/cagalli situation in GSD, so the blond one is the bad guy that needs Charlotte power) and they'll return to their homeland or something similar. In this way Charlotte will have less time and Silvya will gain her screen time.
But those little busybodies will uncover the truth whatever it would be. And Teppei would have his time to understand his strong feelings toward Charlotte, just in time to save her again and the whole world. Ok, I'm not sure about the amount of world

This is a guess in case "lover" is related to the real lover and not the fiancee. but really ...

Ah, I had a feeling the buttler will die.