hopefully the rest of the community responds with some of the specifics you are asking, but take a look at
Lightroom's Help- "optimize performance":
-hope these help in the meantime,
I had already read the first link (in fact I have a shortcut to it on my desktop) and plan to incorporate some of its recommendations into my setup, but it doesn't go into much detail about the tradeoffs for placement of LR catalog, ACR cache, and images.
The second link doesn't have much new except for item 8 "Keep Catalogs Small", which recommends less an 10000 images per catalog and multiple catalogs which contradicts what I have read here.
I found the last link useless (I already know to to tell and control where my images are stored).
Anyone else have any suggestions about where to put the LR catalog, ACR cache, and images to get the best performance, particularly for the library module?