I have a big wishlist. Sometimes, I'd like to be able to easily see how often a book is posted into the system - like if I'm going to a used book sale, etc. I might choose to buy a book with only 3 wishers that hasn't had a copy posted in 4 years than a book with 100 wishers that gets several copies posted a month - KWIM?

I know you can sort by estimate, but not every book has an estimate. And the estimates tend to really jump around IMO - I had 1 book say 66 weeks, then 34 weeks, then 80 weeks - all in the span of a week!

No.  You can sort by the date you added it, by the estimate, and by your position.  Plus title and author.  (With the detail that books without author data are hidden in the author sort.)

Part of this is when folks select to remove the received book from their bookshelf, it removes the received date.  The data is built upon other data we already had in the system.   So the last received data is really dependent on what each of us members do.  Very fickle data.  Makes the estimates jump all over and disappear.