Re Dana's original point, and ignoring the problems of dating etc:
And, by the way, why did the Federation have to go to the trouble of actually conditioning kids to believe that they were molested by Blake?
I think it's so that justice can be seen to be done, especially by Varon. cf the scene where Glynd assigns him to the case, and says: "I'm aware that I needn't say this to you of all people, but I will say it because I feel so very strongly about this case. I want you to do everything in your power to help the man. Our first concern must be to see that he has justice."
Varon is portrayed as a man well-known for his integrity; Glynd and co deliberately select him for this reason. They want him to be completely convinced of Blake's guilt, and to be able to tell any doubters afterwards that he's sure the trial was fair. Providing real live traumatised children was an important part of this.
Their mistake was to underestimate Blake's persuasiveness (probably because they didn't believe he could have renewed his forceful personality so soon). In fact, he's come on so quickly that he's able to analyse the situation very accurately: "The Administration has gone to enormous trouble - I mean, they've even put themselves at risk. There must be a number of people involved who know the truth. Now why? Why would they take that chance?" He correctly concludes that the stakes were high, and other methods of removing him from the scene politically undesirable.