At L1,an Alchemist gets 2 formulae, plus a number of bonus formulae equal to his Intelligence modifier. If an Alchemist's Intelligence score increases later on, such that his modifier increases, does he gain retroactive bonus formulae? If so, do they need to be L1 formulae (all he would have had access to at level 1), or can they be of any level he has access to at the time of the ability score increase?
There's a bit written here about Intelligence that suggests that all bonuses are retroactive, but this seems like a character-creation only sort of thing... I imagine it's the same for an Alchemist as it is for a Wizard...