Hi Sascha,
I’ve definately been able to capture BD output through analog component in the past. The tricky part is making sure your setting are correct. Some players will send a 30hz signal instead of 29.97hz or 23.98hz… Try a couple of settings to see if one clicks.
A better tip I have for you is to use AnyDVD to rip the discs, copy the m2ts file and then bring that into premiere natively. Make your selects and export a QT of your choosing. Works really well.
Hope that helps.