Hi Michael.
About the first unread post, at the top right side of the thread there is a link that do what you ask for. Click on it and it gets you to the "First unread post" inside the thread.
About the spell check function the board itself do not have this functionality.
I would recommend you to install Firefox Mozilla browser. There are spell check dictionaries you can download and install (many different languages). Once those are installed, every time you write something in the post window the spell check is working for you.
For example, I have installed the Spanish, USA English and Swedish dictionaries and use them all the time. Before you start writing, right click in the blank text space an choose from the floating menu the last option (Spell check on). Then, when you start writing, the words that are wrong spelled gets underlined with a red dotted line, if you right click on that word the floating menu will give you options to what you wrote wrong. You can also change dictionary on the fly. After more than 2 years of using Firefox and it's complements I sure could not go back to IE. Give it a try. It's free:
FirefoxHappy typing!
Peter Holmquist.