@Ormael: it wouldn't make sense for you to be a bimbo and not talk in Ditz Speech, it's one of the defining factors. And unlike the other effects, it's not physical.
Uh, maybe just don't give your PC the Treatment or Dumb Fuck? Not sure why you would turn your PC into a Bimbo in the first place if that's not what you wanted. If you just wanted better assets there are plenty of other TFs.
It is simple, in fact, The bimbo fetish greatly appeals to me, but only insofar as it concerns the hypersexual and promiscuous aspects: the body changes, the look, and the sluttiness. I regard the loss of brainpower as a very annoying and off-putting side effect. My own vision of the bimbo ideal includes decent smarts and its application to the PC makes Steele someone that hacks hard, fights harder, and fucks hardest. I give my PC the Treatment, Dumbfuck, and Gush to tap in the hypersexual body and slutty mental changes. The former can sometimes be gained by other TF sources, the latter not so much, and in any case the more the better, so I pile up such changes from any available source. Loss of Int is a very unwanted side effect, and as a matter of fact I do counter it by rebuilding Steele's Int to maximum, just like the physical changes. I mind the loss of WP much less, since I can view it as part of the sluttiness aspect. I do not mind ditzy speech so much when it seems somewhat appropriate and sounds cute/sexy, in friendly or seductive talk scenes. It grates on my nerves when it gets used with openly hostile NPC or in socially inappropriate situations, such as formal talks with people of high social status. In such situation it just registers as dumb. My Steele has more than enough brainpower to know when ditzy speech may be fitting and when a different tone would be necessary.