Yeah, I do that actually really often. I'd type a message, read it and be like.. "Nah, the person will think I'm mean" (even if it's something totally not mean >-> ) I'm really glad that there is not a option to be able to see what the other person is typing before it's sent xD
Has started becoming more of a problem for me. I don't want to come off too strong and frighten people. Sometimes I type out a bunch of random stuff and just delete it.