Good questions all. I am personally handling all the affiliate email these days and the address is affiliates@love(you know the rest). By the way, if you leave email addresses in public forms the spam bots find them and you can swamped with spam.
To answer your questions though:
1. Once a potential customer enters Love-Scent.com from your website one time, you will get your commission as long as they order something within a certain length of time. It tells in the welcome email when you register. I think it is 45 days; I don't recall at the moment. It doesn't matter how they enter the site from then on, or how many times they order. As long as they order within the time limit, you get the full commission.
2. You can make the website in German if you want; then send the customers directly to the various product pages. Just depends how hard you want to work on it.