I'm not sure if this is an advice one or a rules one, kind of both. I was wondering if anyone has gone with the idea of making a dice of sneak attack on a rogue swappable (permanently) for say a precise attack damage bonus ala Swashbuckler, so for example
At level 9 a rogue usually has a 5d6 sneak attack, if swapped, they'd gain an 'at level' flat bonus. So 9. Now yes, on average that's a lot lower roll than the 5d6 would give, and at level 20, 20 out of 10d6 is also kind of a low roll, if they've got deadly sneak that's generally a minimum 'roll' of 30, but the added benefit of this swap would be like a swashbuckler, where they don't need to jump through the usual hoops to 'use' sneak attack, so they don't need to flank or catch something without their Dex bonus.
So in a sense, in both a straight up fight and a 'sneaky' one, the swapped Rogue does consistent damage, while the regular/unchained rogue does less dmg potentially in a straight fight, and potentially more in a sneaky one.
Then:
Should this swap also mean that this rogue is ineligible for talents that boost Sneak attack (since this isn't 'sneak attack') so you don't have every attack doing Strength damage too, etc. And if you disallow those talents for this swapped precision attack, what would be an appropriate buff to balance it, or is a straight swap even with denied talents still balanced?
Use Piranha Strike with a light weapon:
http://www.d20pfsrd.com/feats/combat-feats/piranha-strike-combat
Weapon options:
Use a Wakizashi (and perhaps flavor it as some version of a Rapier that counts as light for the feat eligibility).
Use a Rapier with Effortless Lace.
Use a Kukri and live without the 1 extra average damage.
If you are Unchained Rogue, you'd have the prerequisite Weapon Finesse already.
Of course, the Piranha Strike drawbacks are:
penalty to hit akin to Power Attack,
coupled with the Rogue's already mediocre BAB, plus
damage scales worse than the Swashbuckler's ability of Precise Strike or a Rogue's Sneak Attack.
Maybe you can just get the GM to give you the Swashbuckler's ability of Precise Strike as a straight swap for Sneak Attack.
Other ideas from D&D can be gained from here:
http://www.giantitp.com/forums/showthread.php?273034-Skilled-Adventurer-Cla ss-(Also-Is-there-a-rogue-variant-without-sneak-attack-)
Getting [fighter] Weapon Training and/or [slayer] Studied Target may be other good options at GM discretion, but [swashbuckler] Precise Strike seems like your best option for damage [though the other two do include a bonus to hit in addition to damage].