

Standard USB 3.0 is 5gbps, which is quite a bit faster than a hard disk drive so if you get a basic USB adapter it will perform about as you would expect a hard drive to perform just a bit worse. Direct Attach Storage will be many drives connected over USB and then you might run into limitations as the number of drives increases as USB tends to top out about 350MB/s with drives.
I have just let it grow organically. The front page is an index of various topics from personal things and particular games to household information. Then below that there might be just a page or an index to a bunch of pages often starting just as a list of links. I am often refactoring once a page has a bunch of sub headings of related topics but ultimately now needing multiple pages and replacing the original with the index to those pages. I don’t think I could have designed an index system from the start without the content because I wouldn’t have known what I was going to store.