Europe, generally, is quite safe. Personally, I think my regime is a little overkill, but as you say "your bike is everything!".

When I stay in big Cities (I love Paris, for instance), the Hotels I use have underground parking - VERY secure! I always use my disc lock, and I also have a bike chain that I wrap around something immovable if parked above ground. If it looks like it's going to take effort to steal, my thinking is that people move on to easier prey - I'm working on the assumption that theft is often opportunistic.

Watching a lot of the HU DVDs, one thing that comes across from many travellers is the use of a bike cover; the more beat-up, the better! Mine was VERY cheap (and looks it - no logos and cheap material), has been ripped a few times and I've patched it together with duck tape. It looks even worse! But that's the point; it almost makes the bike invisible. I appreciate this sounds stupid, but you'd be surprised how little attention it gets when covered up. I was at a campsite in the Czech Republic a few years ago. Bike covered up, no attention at all. Cover off ready to get packing, swarms of people paying attention to me and the bike.

At hotels, I always just lift the panniers off and carry them to my room. Partly for security, partly because it's the easiest way to take my stuff with me. In Morocco, I've always tipped the security guy as well - nothing too much, but "keep an eye on my bike "!

Safe travels and don't over think things!