Plot has always been the hardest part of writing for me. When I'm ready (by 'ready', I mean 'the plot is in a sufficient state of completion that I feel comfortable to start writing the actual meat of the book - dialogue and so forth'), I'd like to get it critiqued. Would it hurt my chances of getting published if I posted the plot, but did not post the actual novel?
Plot (storyline, to be more accurate) is not critiquable. The story idea means nothing. The execution is everything.
Don't. You're better off posted an excerpt and let us help you see if something needs to be done better. And, like Cogito said, execution is everything. The only things you should worry about when it comes to plot are plotholes and making sure things make logical sense.
the best plot in the world can bomb, if the story/book is written by a poor writer... and the worst plot in the world can be a bestselling award-winner, if handled by a good writer... so don't waste your time trying to get opinions on your plot... write the story/book and then ask if that's any good...
If you are struggling with certain plot devices, or you feel like you story is too convoluted, then I would say to talk it out with a friend. I have a couple of writing buddies who I discuss most of my stuff with, and they help me look at my work with a different perspective.