I am willing to beta. Squicks: Unrelenting angst and unhappy endings. I see Too Much of that in RL for me to have any attraction to those, so I would not be able to focus and perform as a good beta. Overly effeminate, weak Harry, or other guys. I tend to take that is a sideways put-down of women, so I don't take it well. Willingness to accept humiliation as a way of life is also a squick for me - refer to above.