So, say my Eidolon has four attacks, and has taken the feat Exotic Weapon Proficiency (Bastard Sword) and Multi-Attack. He has two arms, in which he hods a pair of bastard swords.
The questions are:
Would he have two bastard sword attacks, or four?
And
Would these attacks be at a penalty (other than the one Multi-Attack gives?
Second Scenario:
A synthesist summoner has three levels of Monk, cause the Monastic Legacy Feat is pretty much awesome. Because of the Monk's Unarmed Strike rules working as both natural and weaponized attacks, could this synthesist summoner (Eidolon has for arms, but not the Claws evolution) do the following:
Use his Unarmed Strike Damage, from appropriate Equivalent Monk levels, and get four attacks using that damage?
And
Would he be able to apply Reach and other similar evolutions to the Unarmed Strike?
So, say my Eidolon has four attacks, and has taken the feat Exotic Weapon Proficiency (Bastard Sword) and Multi-Attack. He has two arms, in which he hods a pair of bastard swords.
The questions are:
Would he have two bastard sword attacks, or four?
And
Would these attacks be at a penalty (other than the one Multi-Attack gives?
Second Scenario:
A synthesist summoner has three levels of Monk, cause the Monastic Legacy Feat is pretty much awesome. Because of the Monk's Unarmed Strike rules working as both natural and weaponized attacks, could this synthesist summoner (Eidolon has for arms, but not the Claws evolution) do the following:
Use his Unarmed Strike Damage, from appropriate Equivalent Monk levels, and get four attacks using that damage?
And
Would he be able to apply Reach and other similar evolutions to the Unarmed Strike?
1. You'd get a number of attacks based on your BAB with your primary hand bastard sword (for intstance, a level 7 summoner's eidolon would get two attacks with it at +6/+1 BAB), and one additional attack with the offhand in accordance with two-weapon fighting rules (you'd be attacking with a -4 penalty, and that's if you have the Two-Weapon Fighting feat). If you had improved two-weapon fighting, you'd get a second attack with the offhand in accordance with that feat.
Using primary natural attacks will work significantly better than dual-wielding bastard swords. Instead of attacking at BAB +2/+2/-3/-3 with two-weapon fighting and improved two-weapon fighting, you'd make attacks at BAB +6/+6/+6/+6 without having used any feats (assuming level 7 here).
Multiattack has nothing at all to do with manufactured weapons, and only has any effect on natural weapons.
2. No. Monks cannot attack with their unarmed strikes as natural weapons. They still attack with unarmed strikes as manufactured weapons. They simply count as both for the purposes of spells and effects.
He could apply the reach evolution to unarmed strike. He doesn't even need to be a monk to do that, he just needs to have an unarmed strike attack, since reach does not require the attack to be a natural attack.
As far as anything besides reach, he cannot take it. As far as I'm aware, the Eidolon would have to qualify for the evolution separate from the synthesist. The eidolon is the one taking the evolutions, you just temporarily gain the use of them when fused. So it could not use Improved Natural Attack on your unarmed strike, for instance. You could use aspect for that if you're a monk and you get far enough in synthesist, though.
FAQ Entry for Synthesist
I think you were thinking of Multiweapon Fighting for the first example. Its like TWF, but has a lower entry point (Dex 13, 3 or more Hands) [They can be claws]. It has the same effect as TFW, but no improved version. It is legal for a Monster to take TWF (Inner Sea Book has one in the monster section)