Just looking at the FM2015 Help, it appears that the footnote feature has not been enhanced since adding Unicode support at FM8.
If what you wanted was endnotes, the Help file merely documents the Xref hack users developed long before Help picked it up, complete with the limitation of you needing to keep track of the order of appearance in the text body.
Can it split footnotes?
I wish! You can request it here: https://bugbase.adobe.com/index.cfm?event=newFeature
Right now, if the reference number and entire note don't fit on the same page, the note moves to the subsequent page, leaving the number behind. I run along behind (on the final draft) and force the reference numbers on to the correct page. Total pain in the you-know-what!
Note that you can use InDesign for footnote-intensive documents. I lay out several legal journals in InDesign, and it handles footnotes seamlessly.