I tried a search on this but couldn't find anything.

Silver Surfer gets Support and a 12 Defense late dial could he "Defenders TA" his Defense to someone Wildcard or Defenders TA and Heal them using the low defense?

yes he can because it replace not modifies the DV
and so can Dr strange i would know i have asked many times

I don't think so. i think it says somewhere you have to roll against an unmodified defense.

Replacement values are different from modified values, they "replace" the number on the dial as if that was what was printed there.

Does it also work with the Batman Enemies TA since they FAQed it to say. Works like Defend but for Attack.

yeah it works with syn sin too michael used it on me