I find it annoying in an RP when I send a message, and get a reply with nearly everything I sent only reworded, GAH!!! How does that advance the story line. If it's writers block tell me.
Laziness or not being sure where the RP is going.
One liners. I'm definitely an advocate of quality over quantity, but come on. How are one-liners at all supposed to advance the plot? I can understand writer's block, but even in the most severe cases of writer's block I'm able to spit out at least a paragraph.
Mushy and over-dramatic romance in something like a hard-core zombie RP. Or random 8 year old anime girls in a war RP. Personality: Cute, shy, quiet, bubbly, kind, feisty, flirty.
Weakness: Using this power is tiring.
Well no shit Sherlock. Why don't you also include "Needs to eat three times a day" and "Vulnerable to bullets fired from guns" while you're at it. God, non-weaknesses like that bug the everloving crap out of me. You see those everywhere since it's Timmy the Powergamer's way of making his character seem less blatantly overpowered.
Also romance may be even more likely in a survival roleplay given the tragedy and desperation of the characters. Melodrama might not fit, but high tension/dramatic romance may very well.