Well, I am an Eve RP newb. There are a lot of barriers. I started RP-ing because I joined KotMC, which has a number of veteran RP-ers. My previous RP experience was limited to a few DnD runs back in the day. However, I had read a lot of PF and the novel, which is a good read, but not the best RP basis.
The first issue was the process of learning the basic flow. I watched Mercy's Keep and interacted timidly. I started a blog to flesh out Ryven's backstory. I cannot overstate the usefulness of that. Ryven has grown into a complex person and he is very real to me, so much now that I am still surprised by his reactions to things. He is still relatively unknown, but as more people enter his world, he continues to have enjoyable encounters.
I have IRL barriers in the form of time. I work 30hr/week and 18 hr classload at college, plus a wife. RP can be time consuming. If a pvp fleet forms up, I choose that usually.
Some additional thoughts: Ryven is not currently the sort of guy who likes limelight. He has demons he has finally settled and I suspect he will be more public in the near future. So, his IGS interaction has been limited, but I feel generally well recieved, when any bothered to respond to it.
That brings me to the last item: respond to the lesser known entities in a thread. It is easy to engage with the powerhouse characters, but it is unspoken encouragement when you acknowledge them, even if you aren't nice, IC.