Hi "pokeriste" friends (yes, that's french)

I'v learned that we have to defend X% to be unexploitable, to Cbet or bet or check-raise vilain to exploit him etc. But I have some trouble when I review or when I create my range:

Imagine i'm Button, vilain is BB in a SRP. Here comes the flop: T25r
I don't want to Cbet all my overpair because I want protect my turn range. Even if I know vilain is going to fold very often, I wanna be able to represent a strong and turn sometimes.
This goes when you have a flush draw etc
For now, I split my hands: 70%-30% (I'll check 30% of my overpair on T25r) or for strong draws I split 50-50 (or 70-30 it depends). The thing is I already split my preflop range (Cold call AA sometimes) so on turns et rivers, I only have few strong hand (AA-QQ 12 combos preflop, 4 when I check the flop....)
A friend told me I was crazy to do that thing in NL4 (against reg ONLY but still). I'm sure that can't be awful I mean I'm harder to play and less predictible. Plus regs are not use to that type of play
Do you apply that kind of play? How low can you fall (15?25%?)
If you don't how do you balance your range? I'm not looking for answers: "yes it's good!" "No you shouldn't" I really want to have discussion. I may be wrong but I wanna know why,etc (Isn't the strategy part that we love in that game?)

Good luck!