3 questions on pagination of actual blog post article content (not blog post index pagination).

Hey folks,

What are some good methods or specific plugins that will specifically do any or preferrably all of these things?

1. For blog post article content, allow for defining something like after x paragraphs or sentences or words or however to make it paginate to break up content?

2. When the article/post is paginated, allow for a button that is easily seen that can be clicked to allow the entire post/article to be seen without pagination (or otherwise a "show all" button)?

and finally . . .

3. Maybe a little more of a new idea but to enable a way that will force a button click the the next pagination page after scrolling down a certain % of the screen (this would force the next page and also help bounce rates). This one can be a bit of a side option if this a available out there?

All 3 items can have plugin solutions, IF the plugin recommended specifically does one or more of these things OR can be some simple code to a file OR some CSS etc? All recommendations are on the table to be requested. However, the fastest and simplest and most effective ideas are preferable if possible please (and I will add perhaps the most fun to work with vs. nightmarish solutions . . . lol)?