I'm not sure if I got your question right but
You already apply the ability modifier to the 1d4 attack with Polearm Master.
This is from the sage advice compendium:
Polearm Master Can I add my Strength modifier to the damage of the
bonus attack that Polearm Master gives me?
Yep! If you have the feat
and use the Attack action to attack with a glaive, halberd, or
quarterstaff, you can also strike with the weapon’s opposite end as a
bonus action. For that bonus attack, you add your ability modifier to
the attack roll, as you do whenever you attack with that weapon, and
if you hit, you add the same ability modifier to the damage roll,
which is normal for weapon damage rolls (PH, 196). A specific rule,
such as the rule for two-weapon fighting (PH, 195), might break the
general rule by telling you not to add your ability modifier to the
damage. Polearm Master doesn’t do that.
You don't need the Two-Weapon fighting style to do that, it's already incorporated in the feat.
Oradin
Usually SAD builds on a mental attribute work well with pure casters (with Charisma you can get Sorcerer or Oracle), so the DD of your spell can go very high. The downside is that it doesn't work so well with multiclassing (with a 2 levels dip in Paladin you get your spells two levels later). Also note that getting your Charisma to damages is quite useless for a pure caster.
There is no way that I know of to directly get the real effect of Divine Grace without being a Paladin (or Antipaladin). There was a feat (Divine Protection), but it has been nerfed to oblivion. However the Oracle of Nature can get Friend to the Animals as a revelation:
Add all summon nature’s ally spells to your spell list. You must still select these spells using your allotment of spells known. Animals within 30 feet of you receive a bonus on all saving throws equal to your Charisma modifier
So if you manage somehow to be an animal you won't need to be a Paladin. I guess you can find 3rd-party races that are animals, but I don't know any of them.
You can get your Charisma to hp by becoming an undead (like a Lich). I doubt your GM will let you be one at character's creation unless you take an undead third party race.
No way that I know of to replace Intelligence for skill points by level. The best way to do skills with only charisma is the bard's Artistic Versatility, but it doesn't worth the dip if you don't intend to invest more in the class.
Divine Techniques from Divine Anthology (like Way of the Shooting Star) doesn't ask you to be of the same alignment as your deity to be used, just that you worship her, so you don't need to be chaotic good.
Leadership is a very powerful feat, and it becomes even more powerful if you have high Charisma.
Example of a build that works: Paladin(2)/Oracle of nature(5)
Race: Halfling
Traits: Magical Knack(makes the multi-classing more efficient) + one fluff thing of your choice
Feats: lvl1: Noble Scion(war), lvl3: Divine Fighting Technique(Way of the Shooting Star), lvl5: Extra Revelation, lvl7: Leadership
Oracle revelations: Nature’s Whispers, Bonded Mount, Friend to the Animals
Role: Take a heavy armor, a shield and a starknife and ride your boar to battle! You two are practically immune to magic with your saves and have a high AC because of your armor and Nature’s Whispers. You don't deal as much damage as martial characters, so don't hesitate to spend actions to heal fallen ones, but otherwise you should better keep your spells for pre-fight buffing, post-fight healing, or in-fight invocation of natural allies. At the same time your cohort can do cohort stuff that will highly depend on what your GM will let her do. Outside of combat you are the group's face. You smile and look pretty and let others do the stealthy investigations.
Best Answer
Both are considered legal and accepted versions.
As written, they are different feats that share the same name and similar mechanics. Much like how the Pact Wizard (Familiar Folio) and Pact Wizard (Harrow Handbook) are wizard archetypes with the same name but are different from one another.
The Divine Fighting Technique feat in the Weapon Master's Handbook requires you to have the same alignment as the Deity whose technique you're using, it lets you choose an option from those listed under Divine Fighting Technique in the Weapon Master's Handbook.
The Divine Fighting Technique feat in the Divine Anthology requires you to worship the deity whose technique you're using, it lets you choose an option from those listed under Divine Fighting Technique in the Divine Anthology.
Pathfinder Society, Paizo's organized play campaign, has introduced a house rule that allows you to qualify for options listed under one of the feats which only having the other feat. This requires you to still meet the alignment or worship prerequisite for the other feat.
Campaign Clarifications: