The spell Magic Jar allows you to possess a nearby creature. The spell states:
If you are successful, your life force occupies the host body, and the host's life force is imprisoned in the magic jar. You keep your Intelligence, Wisdom, Charisma, level, class, base attack bonus, base save bonuses, alignment, and mental abilities. The body retains its Strength, Dexterity, Constitution, hit points, natural abilities, and automatic abilities. [...] You can't choose to activate the body's extraordinary or supernatural abilities.
How do you calculate skill modifiers while in the host body? I would definitely recalculate any racial bonuses, but are all skill ranks considered "mental abilities", even for skills such as Fly and Climb?
Even trickier is the matter of feats. There are purely mental feats such as Spell Focus, and then there are feats which seem purely physical such as Fleet and Toughness. Then there are feats like Dodge and Step Up which seem to fall between these two categories.
Is there any good way to determine which feats can and cannot be used while in the host's body?