I've not that much experience in austria, but a laufhaus is typically a flat where girls rent small rooms to do their business. It isn't renowned for the best service and I don't really go there anymore. The biggest area with laufhauses is actually in Frankfurt near the central train station. If you like the clubs, you might go to funpalast as well.

I've heard decent things about the sexy sauna in Prague (also very centrally located), but ofte with the caveat that it isn't Germany. I don't know about other Czech clubs, but 900 for 2 hours is laugh out loud ridiculous to me.  

Frankfurt: that would be my choice. But World is really not that good lately, thinking about maybe Mainhattan could work out as well. Or a revisit to Sharks or Oase.

Saarbrucken has the Paradise, but there are a handful other clubs in that area as well. They cater mostly to people from France. I've never been, but reports are usually less than positive.

Golden Time and Livingroom are a good idea on the same day. Golden time is busy early on. but it can slow down as early as 8pm (club is only open til 1 on weekdays). Livingroom doesn't really get going till at least 6 pm and is open til 4 or 5am. If you want to do the combo, you can get a coupon for 25 reduction in entry when you leave Golden Time. They have the same owners.

In the area of Duesseldorf you have dozens of clubs, I personally hardly ever go to GT or LR, but they probably are two of the better places to go to if you have no idea what you want. You might also have a look at Magnum or Oceans even. Big clubs (with mixed reviews), many girls and in Duesseldorf itself. Acapulco or Acapulco gold are also options. Prices are lower and in Acapulco you will find many pretty young Romanians, service is hit or miss. There are also plenty of clubs for your BBFS requirements, but I realise that is a specific niche.

For the best parties you have to go to Cologne: either Samya or Mondial