Only if the eidolon has more than two limbs that can make attacks. A creature cannot normally make more than one natural attack (claw, pincer, slam) with each limb (basic rules for natural attacks).
The "alternately" in the description means an eidolon with claws as part of it's base form can replace their claws with slams as their natural attacks; it doesn't in any way give them additional natural attacks by itself.
Depending on how comfortable you are with cheese, you CAN give your eidolon claws on its feet. You can only do it once, so you only get that one set of claws, but if you're looking for more attacks that's a way to do it. Going for a Hulk-like eidolon, I'd personally suggest going for a Vital Strike build.
Depending on how comfortable you are with cheese, you CAN give your eidolon claws on its feet.
No, different evolutions. note that pincers are bludgeoning only, claws are S/B.
Also note with unchained summonerit is pretty clear that no pincers on the feet. You need limbs(arms) and the number of pincers can't exceed your arms. Also inferred in the APG summoner.
It could be stated clearer, so there is room for argument about RAW, but RAI is pretty clear. Check with your GM.
Assuming you are an APG summoner, yes. Unchained eidolons don't have an option for hooves that I could see.
Is the slam evolution considered one handed or two?
Two
Eh that's annoying lolz x.x but thanks, trying to make a Hulk like eidolon without using too many arms x.x
You can get a perfectly fine attack routine without extra limbs. Or even without more than one natural attack. Or should I say, natural weapon. You can get plenty of attacks with that one weapon.
First, if you only have one natural weapon, you get x1.5 str and power attack. Nice, but you want more than one attack, right? But you can get multiple attacks with that one weapon. Here is the break down:
1- base attack
2- Haste
3- multiattack ability (eidolons and animal companions get an extra attack with their natural weapon if they have only 1 or 2 of them; it is at BAB-5, an iterative basically)
4- Cornugon Smash+ Hurtful- a great feat combo that lets you intimidate as a free action and get an attack in on an intimidated enemy as a swift action.
And just so you know- based off of animal companion stat blocks, you still get x1.5 bonus even when you get multiple attacks. So with this, you get 4 attacks, 3 at full BAB, and they hit like a 2 handed weapon. Heck, grab somehting to bring up the slam's damage up a step (improved natural attack feat, that one evo, just being large, etc), and they are all basically great sword hits.
So you can make a perfectly fine hulk character.