Thank you so much for the kind words and glad you like it~ ^ ^
This might hurt us both, but I think I should tell you that Reynald is a human : I mean I'm happy you like him, yet I'd hate to disappoint :')
To your questions:
1. Secret's for now~ and Koslov does know about him being a soldier ( a sergeant even)
2. It will be on them separately. For example, if you choose Dimitri, then you won't be in Reynald's view anymore. The protagonist is not Reynald anymore but Dimitri. And in his route (Irene or Marcus) there will be someone introduced as his love interest (I copied this but what the heck XD). It will not be between them, except Irene perhaps as she's Reynald's girlfriend.
3. Koslov in a uniform? That's for you to find out :3
Well, I hope that answer you questions~ happy new year too~