Half-(orc,elf,hafling,dwarf,etc.) templates

[Viktyr Gehrig]

I would go with the assumption that non-humans simply are not interfertile, and the reason there's so many half-humans is that humans are like dragons and outsiders in that they are capable of breeding with almost anything.

Thus, dragons and outsiders have templates for breeding with things. Humans can spend their 1st level bonus feat on some unusual racial heritage, gaining some of the powers of the other race, the corresponding subtype, and possibly the ability to take Paragon and Prestige classes meant for that race.

Probably take you all of ten minutes to write up heritage feats for most of the races you're interested in breeding humans with. And then, if you don't buy the "humans will mate with anything" theory of why all the hybrids are half-human, you can allow other races to purchase those feats.

Of course, humans are the only race that can take two racial heritage feats at first level on top of a template that makes them half something else. The most impressive human racial ability is their ability to spontaneously generate 17 grandparents.

 

[Nellisir]

Elven Blood

(General)
Prerequisite: Character may not be an elf.
Benefits: For all effects related to race, you are considered an elf. Add Elven to the list of bonus languages available to you because of your race. In addition, you gain one of the following benefits. This choice is permanent.

• Keen-eyed: You gain low-light vision, a +2 racial bonus to Search checks, and the ability to make a Search check to detect a secret or concealed door as if you were an elf.
• Faerie kith : You are immune to magic sleep effects and gain a +2 racial saving throw bonus against enchantment and illusion spells or effects. Sylvan is an automatic language for you.
• Wild blood: You receive the Martial Weapon Proficiency feats for the longbow and shortbow (including composite versions of each), and a +2 racial bonus to Spot and Listen checks.
• Mixed-blood: For all effects related to race, you are considered to be either an elf or your normal race, whichever would be more advantageous. You also gain a +2 racial bonus on Diplomacy and Gather Information checks, and Elven is an automatic (not bonus) language for you.

Special: You may only take this feat as a 1st level character. If you take this feat at first level, you may take it once again at a higher level, choosing a different benefit.

 

[Will]

What I'd consider doing is racial feats and racial class alterations, locked to 'full X'/'Half-X'/'Slight X'. And perhaps some cultural feats/alterations.

So, a full-blooded dwarf might get up to two Enduring Earth feats, giving +1 Con each. A half-blood dwarf might be able to pick one.
A half-blood dwarf or someone raised among the dwarves would be able to pick Earth domain as a cleric, regardless of deity (either due to racial connection to the Earth, or exposure to dwarven customs and traditions).

Etc.

It'd provide a bit more latitude...

As a template, I'd take a look at diabolic and celestial templates as a guide, or maybe elemental (from ... one of the MMs, I forget), torque it down a little.

I like the first approach more because it's not quite so rigid, and you don't have to struggle with 'give enough stuff but not worry about LA.'