A 465

No. The Flaming property on a vanilla sap deals fire damage.

A 466a

Yes, PCs count as creatures.

A 466b

The aforementioned wizard would be able to use all three attacks as a full round action, taking a -5 penalty on the secondary attack(s). The primary attack is the one(s) specified in the 'Attack' option.

From the d20 SRD
Quote Originally Posted by d20 SRD
Full Attack

This line shows all the physical attacks the creature makes when it uses a full-round action to make a full attack. It gives the number of attacks along with the weapon, attack bonus, and form of attack (melee or ranged). The first entry is for the creature’s primary weapon, with an attack bonus including modifications for size and Strength (for melee attacks) or Dexterity (for ranged attacks). A creature with the Weapon Finesse feat can use its Dexterity modifier on melee attacks. The remaining weapons are secondary, and attacks with them are made with a -5 penalty to the attack roll, no matter how many there are. Creatures with the Multiattack feat take only a -2 penalty on secondary attacks. The damage that each attack deals is noted parenthetically. Damage from an attack is always at least 1 point, even if a subtraction from a die roll reduces the result to 0 or lower.

A creature’s primary attack damage includes its full Strength modifier (1½ times its Strength bonus if the attack is with the creature’s sole natural weapon) and is given first. Secondary attacks add only ½ the creature’s Strength bonus and are given second in the parentheses.
Bolded portion is the relevant quoted section of the rules.