How long does it take to bind books like that?

It's very quick! Niennanir gives a brief rundown of about how long you should wait between construction and completion, but the overall process is very speedy! Quote:

"The whole process, not counting drying time, took less than an hour."

Which is more or less true - depending on how long you spend setting up your pages in your word processor (it took me a few tries to get the margins set to where I wanted them, but once they're set, you're good for any future projects!), you really are going to be spending most of your time waiting for the glue to dry so you can go to the next step lol

Everything else is quite interactive, but in a gentle way which I really like :D I find proofreading and folding the pages calming, and scoring and folding the covers feels very cool >:3c

The only real advice I have to give is that yes, while you should wait for your pages to dry a little before putting on the second glue layer (and also if you wanna be fancy I'd suggest capping the ends as well! Not just the spine itself), you don't want to wait so long that it's gone hard - bubbles can form in between the pages which would normally be pressed by your weights, but if they're left to dry out in the open, your spine will be bubbly and wiggly! This can be hidden by the cover's spine, but it's still better for the overall construction for it to be flat and clean :)