BuddyPress.org

@bergblume

If I may suggest that instead you add to your robots.txt file some wildcard rules such as:
Disallow: *members/*activity*
Disallow: */activity/p/*

as to where I think it may be possible to pull some info from the activity posts to create page titles and other meta stuff, most activity posts are going to be short in most cases, and having a bunch of new pages indexed (even properly with title and meta stuff) is likely to add little value to your site overall – and in fact might create a situation where a bulk of your site pages are considered “thin content” – which would hurt your seo more than any proper page titles will on activity pages.

Considering you are also asking about methods for adding meta keywords, I think you are looking for SEO help that is waaaaaaay outdated – unless you are going for different search engines aside from the big G, bing / yahoo for some reason – in which case my knowledge of the other spiders and their indexing methods is tiny.

Now if you are trying to get proper page titles on your “groups” and member profile pages, I think that would be a worthwhile effort.

Just a few random suggestions, I am not a BP dev or prof coder yet – others may have different advice.

I think that getting and using this info will be better / easier perhaps about WP 4.4 or whenever they include the REST API in the core – and then it should be easy peazy for themes to pull and use this info – not that it should be rocket science to do it now… however I have had no luck getting help with similar issues on other BP pages in the past.

It usually boils down to BP peeps saying that page title and meta stuff should be handled by your theme.. your theme devs will say they use the standard wp_title function (or something like that – which has been flipped around recently) – and that kind of stuff if you want it to be beyond what is “standard wordpress” should be handled by an SEO plugin… my experience with several SEO plugins has been that they will not get into all the BP “pseudo pages” for whatever reason, perhaps because a taxonomy is not registered for them, and that makes it more difficult.

Random thoughts for ya