There is a spectrum of ability and fluency that will always exist in Twitter and #lrnchat.
First, I never measure myself against some of the serial "Tweeps" you find here. :) Yes, its very fast paced and one of the tips on TweetChat is - don't try to read them all...you can't really do it anyway.
Yes, I had thoughts to tweet during the flow ...some I popped on there ...others I felt I missed the "movement" and refrained. Thats OK. I would say I am still a heavy lurker here - I take more than I give and I'm alright with that. I later work to spread or use the ideas afterward (at work, with my own network).
I think the beauty is that #lrnchat is kind of a microcasm of Social Learning as a whole. People come and go, dip in the (knowledge) stream for a few minutes, dip out again. People came late as well. Treat it this way and you'll find more peace with it. For me, again I am 85% a lurker, 15% a contributer. I see a great tweet with a link... I click the link and skim it (therefore I am no longer in #lrnchat) if I like it- I bookmark it for later reading and return to #lrnchat.
When I see a new question I formulate a thought, maybe tweet it ...most of the time I don't. Many times I see a really profound tweet and I decide I want to add that author to those I follow as I hope he/she will add to my growing knowledge outside of #lrnchat as I find they likely blog as well as tweet.
Treat it like a stream filed with knowledge and insight. dip a toe in today ...a leg in next time. Regardless it always leaves me refreshed.