Lightroom Catalogs

The organization of my LR Catalogs has put me in a quandary. Too many questions, not many answers. Do I put everything in one catalog?, do I have one catalog for each year?, should a catalog contain images not on the physical drive that it is saved on?, what happens when my catalog gets corrupted?, how many catalogs should I be managing?, can I search across catalogs?, how many images can a catalog many images should a catalog hold? I was trying to do a search on strategies for setting up and organizing catalogs and came up short. I know when Adobe designed this concept, they had something in mind, but they failed to give some good examples of catalog organization for different scenarios. Like giving you a box of Legos without instructions. Ok, so I came up with my own organizing thoughts, some of which may be based on false assumptions (please tell me if you know otherwise).

Point 1: Only a single catalog can be searched/filtered at one time. The software can point to only a single catalog, there is no facility to search multiple catalogs simultaneously (a great feature to have), at least I haven't found a way to do that yet.

Point 2: Based on Point 1, a catalog should contain all the images that you want to be able to filter and search on in one operation. So, you should not have a separate catalog for 2008 and 2007 if you want to have a collection that contains images from both years.

So, the strategy is to define a catalog based on a type or category of photos that you want to be able to search. In other words, it may not make sense to store your family snapshots and your flower abstracts in the same catalog. Thinking about this, I set up 4 main "categories" of photos I am producing:

1) Stock images (nature, buildings, objects, people, abstracts) that I feel may have some value to be sold as stock or something I may want to someday hang on my wall. A majority of my images are in this category

2) Snaps (family, friends, personal travel photos, ebay shots) are images that have no commercial or art value but satisfy the need to document trips, the kids, or other personal things - like my messy garage before and after...never got to the after image yet.

3) Events (science fair, reunions, weddings, communions, etc.) are images for a specific event that I get involved with (can you take some pictures of Joey's graduation since you have a nice camera??) and has little or nothing to do with my main body of work.

4) Projects, like Photographers for Freedom, which are composed of multiple shoots, but may need to be referenced collectively.

I will define catalogs based on these categories. This seems to make sense to me at this time in my appreciation of LR Catalogs. At least it is a step to avoid keeping all images in one Catalog. As for the answers to all the questions I posed above, I still don't have clear answers. But we have to go with something and I'll let you know what I end up putting together.