I do all (well most) of those things with my Nook Color - I have it set up to run CM7 off the SD card.
Via CM7, you can enable the Bluetooth and pair a keyboard for journaling on the go, or you can download a swype-style keyboard from the market.
The Moon+ reader app is great for highlighting and lets you export your highlighted selections to email, Evernote, just about anywhere actually.
There are quite a few PDF viewers in the Google market - I'm very fond of QuickOffice for zooming.
There's more information in my signature, or you can PM me. Good luck in your quest!