Ok, so with the Swashbuckler now being out along with its new archetype, the Mouser, obviously a Halfling Mouser sounds like a great idea. Which in researching the build brought me to the Risky Striker feat for Halflings and made me think of figuring out a way to cast Reduce Person on myself to be Tiny sized to get the Risky Striker feat against Medium sized creatures.
Now, as being a Tiny size creature you have 0 reach and your best bet is to simply occupy the square of the creature you're fighting (which is possible if I read the rules correctly). You can't flank though.
The root question here is: Can a Tiny sized Mouser Swashbuckler Archetype (who has the Underfoot Assault deed) simply move into an enemies space, and occupy it (without spending the Panache point in order to use the deed) and still benefit from the deed (which gives the enemy a -4 to attack you and you give flanking against that opponent to all your allies) while being Tiny sized?
I hope I phrased that question intelligibly...