My name is Domas, I am the frontend development lead for litecoininvest.com. I will try to answer your technical questions and provide some insight into our development schedule.
-wheres the "lost password" function? what happens if one lost his account credentials?
Password recovery is on top of my list, ETA is tomorrow, maybe even late today. Change password function to follow.
-can you work on the performance? the website has some slowdowns
We are very aware of the intermittent lag issue and are working on it. Expect it solved soon.
-the website doesnt work on older browsers (the content area remains white)
I will be sure to add a warning for older browsers.