Hmm.
I think that there's an interestingly fine line between 'helpful advice' and 'outright pressure to conform'.
I've been in discussions with any number of gender queer/CD/trans*/TS people who were unhappy with the reactions that they were getting from society. When I dug a little conversationally into what their goals were for transition or presentation, the presentation that they put forward didn't really serve what they'd like to have done so I have commented on that in those instances. It's never a fun conversation because intent and reality are very dichotomous things, from time to time.
On the other hand, advice of that sort is something that you have to have solicited. If the person is comfortable in who they are and what they're doing, then those comments are intrusive, arrogant, and absolutely out of line.
As for 'more trans than thou' attitudes? *blech* What the eff ever. There have been many instances of that that I've run across. I have no patience with it no matter who it's aimed at.
I do feel that, most of the time, these attitudes are more a way of the person doing a bit of ego-pumping via denigrating someone else. The persons who tend to do it, I've found, are very defensive, generally look and act uncomfortable with who and what they are. Regardless of what their issues are, however, I'll smack them down every time. No one needs to hear that kind of garbage when dealing with issues like what we have to.