Very good questions! Answers below:
1) Julie must have a clear line of sight to the target in order to "operate". The target must not be farther than 4 spaces. So: a unit in a building can definitely fall in love with Julie, if it has a clear LoS and she's near enough.
2) She doesn't need an order. That's how charming she is.
3) Just wait for the editor: we'll sure someone will write an elaborate fan-fiction about it (for a canonical answer you'll have to wait for a DLC, though
).
4) That's clever, but currently impossible. (*) Julie only seduces the nearest enemy unit (if multiple units are the nearest, she will seduce the one with the lowest order).
5) You're right, sometimes having to give an order is a burden - it happened to me too, in rare cases, especially when someone had opp. fire. I'll try to bring this point to the attention of the rest of the team.
6) Old enough!
(Since her full name is "Julie Aubrac", I guess her appearance could be based on Carole Bouquet...)
---
(*) You're really sadistic with your units! First you want to kill the Rock because he's too slow, now this...
