The best hotel search engine I have used to date is kayak.de, a company from Berlin. The offer most if not all of the features you described and compare a varie

The best hotel search engine I have used to date is kayak.de, a company from Berlin. The offer most if not all of the features you described and compare a variety of different booking portals. I'm not completely sure how biased they are in their ranking. But I've been using this site for the last few years and never had any problems. I recommended this site to a few of my friends who shared my positive experience.