Chances of another season? Don't know.
There is material on which to base another series like the first one.
Maybe how they end F will give a clue about if they have any plans to keep animating or not, but I defiantly would not put money on it.
About the rest of your post-
The whole story of FMP has been split into 2 story types- this is how FMP was first published.
The first series (FMP!) was based on the heavy, serious, thick plot novels, with alot of Mithril stuff, ect.
The second series (FMP? or FMP?F) is based on the fluffy, comedy short stories that are mostly centered at the high school.
The FMP?F series is not a direct contiuation of the first series- its even possible to imagine that some of the F episodes took place between story arcs in the first series (this is the way the manga combines both story types).
The two different story types are told side-by-side, but not directly connected, so don't hurt your head trying to put them together
If they do another series, I (like many) expect that they would do another FMP! story continuing the serious story from where the first series left off.
It will be a while before we know if they will do that or not though.
(Influences to consider for a 3rd series- popularity/success/interest by japanese audience; interest by the creators; a budget for it, along with projected profits; no conflicting projects for any of the main ppl involved; an animation studio (gonzo?) willing to do it...ect ect- no way to really tell unless they make an announcement.)