I think what you're talking about was an option at the bottom of the feed which allowed one to see everything everyone's posted. Unfortunately, upon making the feed endless, this option is no longer available.
Is there an easy way to choose who sees a particular post (ie, the way one sees a display of friends to click on when inviting them to an event)? They should implement this, allowing for deselecting unwanted viewers (rather than selecting for wanted viewers - for those with too many friends).
It's possible to create groups of friends and then when you make a post, set it to display to a particular group. For example, I have 'Gamers', 'Close Friends', 'Coworkers', 'Family', 'College Friends', and 'Hometown Friends' groups (with some overlap of course). When I post something I can target it to the appropriate group of people.
Is there an easy way to choose who sees a particular post (ie, the way one sees a display of friends to click on when inviting them to an event)? They should implement this, allowing for deselecting unwanted viewers (rather than selecting for wanted viewers - for those with too many friends).