The x64 or x32 bit decision would need to be made by someone familiar with your environment and the needs of your users. There is no problem doing either one within the View environment. That same thought process will be required for deciding what will be included in your base. The rule of thumb is if the app will be deployed to everyone in the organazation then why not include it in the base image. From what I have heard the Office 2010 suite is a really tough thing to try and ThinApp.
I'm moving this post from the View BootCamp forum to the general View Forum.