Old Akro:
1) We do not recommend WOT for the climb on the TC'd engines. Only the TN and NA engines. We recommend that you use the top of the green MP as outlined in the POH for your aircraft and climb full rich. The 1300dF target is for non-TC'd engines. Your engine's Target should be around 1150-1200dF, so you;r not very far off as it is. Were I flying your aircraft and wanting to treat it kindly, i would leave it full rich at the climb power setting.
2) Using the max RPM is easier on the engine than a reduced RPM. The thetaPP is later and the peak pressures are lower at higher RPMs… all good things. The differences between 2700 and 2500 are small, so I do agree that it is a minor issue.
3) Cruise is a different matter. The POH recommendations to limit cruise power are based on being ROP and they make sense in that condition. If one operates LOP in cruise much higher power settings are fine since they result in lower peak pressures, wider detonation margins (not really a factor) and cooler CHTs. All of these are positive factors along with the cleaner running combustion chamber.
4) "Continuous operation at fuel flows leaner than 25degF rich of peak TIT is prohibited for all conditions" is a good recommendation for ROP back when everyone ran ROP only. It does not apply to LOP.
5) 25dF ROP is the mixture where the exhaust valves run the hottest. If that's your objective, then that's your mixture!