D F Tweedie
Lawrence .... I'm a relative 'noob' to BIAB, but I can definitely answer one of your questions and 'to the best of my recollection' answer the other.
I simply installed the whole program on a secondary drive. Works fine. As you must have noted, the "BB" folder doesn't normally get placed in Program Files directory like most programs do. This is because it operates in a self-contained fashion. So for operating, every single file you see in the BB directory that is in the root folder, that is not in a sub folder, has to be there for BIAB to use it. Some are required for it to run and some, like styles files, are required to be there for BIAB to use them. Even all the subfolders with the styles must be there for you to be able to play the style demo from the style window directly ... although they could be anywhere just to browse to find them an play them.
Second question ... here's where the best of my recollection comes in, Mac a regular and 'expert' on the PG BIAB Windows forum, claims that current drives are plenty more than fast enought and that there is no performance benefit from placing different elements on different drives other than recording audio to a second drive to minimize possible stress on a HDD between read and write operations. He states that once BIAB is loaded up the program is essentially running out of RAM and therefore should place no additional demand on the OS.
Yes, SSD technology is impressive ... but so are Ferrari's. Most of us get places in more mundane vehicles.
Hope this is helpful.
[Non-text portions of this message have been removed]