While i am not a lifestyle newbie, i am a newbie to this whole online thing. My previous experience (which feels like it was a different lifetime now LOL) was all rl, so i feel like i can answer your question
The number one thing for me, lying. i hated it when they lied to me. I'm not saying you have to tell me your entire life story, but if there is something that you would rather not tell me, then say that ... don't lie!
Then i have met the "submit to me and wear my collar NOW" guy, ... whoa, wait ... i don't even know your name?!
It pissed me off when they would try to rush me, give me a chance to get to know you before i make a decision.
Now i know you said not to bash anyone specifically, but since he is not a member here, and i will not mention his name ... i am going to LOL i was in a brief relationship with a Dom, still in the getting to know each other phase, when he suddenly started communicating less and less. Then he would say things like "I'm leaving work now, be home in an hour, talk to you then" and i wouldn't hear from him for 3 or 4 hours ... i actually sat here worrying about him, thinking maybe he got into an accident or something! The last time he did it to me he said that he was going out for the day and would "check in on me periodically", i didn't hear from him until after midnight that night when he said he was home and going to bed. So, do what you say you are going to do! Doms certainly expect us to.