I'll take a shot at some suggestions for Sacred Fist:
One of the biggest contention spots I've seen people bringing up is the Monk Stances. My suggestion is to create a new stance for Path of Light granted at level 6 as an Adapt stage and auto-grant Master and Grandmaster at level 12 and 18, respectively.
Radiant Stance: You gain +2 Charisma (3/4) at a cost of -2 Intelligence. While in Radiant Stance you gain 'Hit Effect: Gain 1 ki.' and 'When Missed in Combat: Gain 1 ki.' Additionally your Aura of Courage provides stacking Heal Amp while in this stance. Finally while in Radiant Stance you gain MMR cap equal to your Divine Grace bonus. Radiant Stance also counts as a Fire Stance for enhancements, items, or epic destinies.
I think tucking an MRR cap into a stance exclusive to this archtype, while also tying it to the core Paladin class feature, means that this emphasizes a heavy to pure paladin playstyle while also giving them a bit more magical defenses compared to a monk in a manner that reflects the class being a Paladin. +62 MMR cap certainly won't make a robe evasion build the best, but it might be an interesting testing ground to see how it may play out for balancing monks in the future.
Additionally to go along with Radiant Stance, I would suggest a Path of Light exclusive Ki Strike.
Radiant Strike: You strike an opponent, backed with the power of holy flames. Your attack will deal 1d6 fire and 1d6 light damage. On a critical, this damage is increased to 1d10 die and produces a blindness affect on the target. On a vorpal, this attack produces a Sunburst (as per the spell) with a DC based on Character Level + Charisma + Evocation bonuses.
Or something similar, DCs and numbers are entirely up to dev choice. But this would give the Sacred Fist some of the CC people are clamoring for, as well as returning the insta-kill from KotC, at least against undead.
With the changes occurring for handwraps in Swords to Plowshares, you could tuck it into the weapon line similar to KotC to help with feat costs.
And one final note, while not a part of this Archtype or even its discussion, I am curious to ask: is there potential for adjustments to the Razorclaw Shifter's tree while we're looking at non-monk handwrap users?