A1. You need to create a PBworks account first. Go to https://my.pbworks.com/?p=create to create an account. Once you've created an account and are logged in, return to the Science Hack Day wiki and click "join this workspace" on the right. Now you're setup to edit any page on the wiki without having to deal with this unintuitive process ever again, yay!
A2. When you're logged in and are viewing the Science Hack Day wiki, click on your name in the upper right corner. You'll then be shown different notification options under the header "Preferences". Select "Send notifications only for my starred items". You can then "star" what pages you want to receive updates on by clicking the star that appears next to each page's title.
A3. PBworks can sometimes be wonky. You can make your edits more accurate by directly editing the HTML. When you click "Edit" there will be a button called "Source" that is displayed. Flip this button on/off to toggle between the HTML & Preview mode.