Hi Abi,
Kindly find my response to your inquiries below:
(1) Go to profile types - Custom fields - then see that 'Select Custom Fields' on the RHS is sticky.
-> I'm not quite get what you mean here. Do you mean the 'Select Custom Fields' section on the RHS is sticky as we scroll down the page?
http://screencast.com/t/rGK89TGf1
If yes, this is our default behavior where the section will be sticky as you scroll down the page ( Where this was a default behavior in our previous version as well)
(2) The 'Checkboxes'field can't be edited.
-> I've replicate this issue locally, seems there is a bug in our end. I've logged this issue in our issue tracker, and our developers will take an action. We will keep you update on this
Thanks for the report Abi