1. Advanced search on Member List is gone - is there a button to enable this somewhere now?
Control Panel > Members
Select which fields are available for Advanced Search.
If it still doesn't appear then chances are you have Quick Search turned off under Social View Settings. It is enabled by default.
We are aware that turning off Quick Search shouldn't necessarily hide the Advanced Search link as well. We will add an additional setting in an upcoming release.
2. Go to profile > select Friends tab > scroll to the bottom and select the next page of friends. This will refresh the page and take you back to the Activity page.
Yes, this is pretty annoying. It's actually paging properly just not setting the correct view on the tabs. This will also be corrected shortly.