Replacing an attack roll with a skill check - which modifiers apply?

[Covert Operator]

Which modifiers would apply to skill checks rolled when attempting combat maneuvers?

Flanking
High Ground
Improved [maneuver] feat
Weapon Focus feat
Heroism
nonproficiency with armor (penalty)
Dazzled
A penalty on attack rolls from any unique ability.

Unchained Rogue Talents wrote:

Dance of Disorienting Shadows: A rogue with this talent can attempt a Perform (dance) check in place of a combat maneuver check when attempting a reposition combat maneuver.

Weapon Snatcher: A rogue with this talent can make a Sleight of Hand check in place of a combat maneuver check when attempting to disarm an opponent.

[Mysterious Stranger]

You use the full modifier of what you are using. So, if you are using a skill to make a combat maneuver check you use the bonus to the skill as if you were making the skill roll including any modifiers that would apply to the skill roll. You do not use any modifiers that would apply to the attack roll, unless they also apply to the skill roll.

[Covert Operator]

Thanks! That's convenient for my Spear Fighter build; I'll be accumulating a massive penalty on attack rolls.

[Mysterious Stranger]

Keep in mind that a lot of modifies apply to both attack rolls and skills, especially penalties. The armor check penalty and non-proficiency penalty for armor applies to all attack rolls, DEX and STR ability checks and skills. Most conditions do apply the penalty to skill rolls.

[VoodistMonk]

Spear Fighter's Spear Parry ability gives a cumulative -4 on all following attacks... I'm guessing this is what Covert Operator is trying to get around. Probably just a three level dip in Fighter for an UnRogue with a... Elven Branched Spear? Dex-to-DMG as well as OP&R with a reach weapon... yes, please. Lol. Or maybe just a three level dip in UnRogue for a Fighter with a Branch Spear. Either way... I doubt it's gestalt.

However, the Elven Branched Spear lacks both the disarm and the reposition/trip special weapon qualities... so I very well could be wrong there.

[Mysterious Stranger]

The downside is you don’t get the bonuses to the attack roll to the skill. So, the flanking, high ground, improved [maneuver} and weapon focus bonuses do not apply. If the weapon is magic, you also don’t get the enchantment bonus either, nor do you get any bonus for the weapon quality like trip or disarm.

[Claxon]

And while you can get a lot of bonuses to skills, sometimes those bonuses are to specific applications of a skill. Anything that is a bonus to a specific application of a skill, wouldn't apply to these uses of substituting skills for combat maneuvers (unless of course that specific bonus was for exactly that thing).

[Covert Operator]

Thanks, good point on the armor nonproficiency penalty also applying to skills. Here's the build explanation!