What about “with no due respect”?

Saying it before something that is not disrespectful would be redundant at best and very confusing at worst.

"With all due respect, how's the weather today?"
"I'm not racist but I prefer tea over coffee."
"I'm not a pedophile but I think terminator 3 is a bad movie."

It could also mean something like, "I am going to challenge your opinion but don't intend it as a challenge to your position". Or even, "I respect your opinion and think you might be right, but I don't understand it, so here's the thing that has me confused so we can clear it up and get on the same page".