Re: Show Categories in tabs and drop down menus at top?
As @rogercoathup suggested, using a child theme is THE way to go. You’ll find all the info you need to learn how to create one (and why you should) here:
https://codex.buddypress.org/extending-buddypress/building-a-buddypress-child-theme/
(Watch out… shameless self-promotion coming up 
)
Once you have your child theme up and running smoothly, may I suggest trying my plugin: Add All Nav Links to BP-Adminbar. The plugin allows you to add pretty much whatever you want to the adminbar, style it to match the overall look and feel of your theme, and even to replace the main theme navigation with your customized adminbar. (It only modifies the adminbar on the main site; sub-blogs remain as they are.) Check it out here:
https://buddypress.org/community/groups/add-all-nav-links-to-bp-adminbar/
Hope this helps!
