When was the ban on gay people serving in the US military lifted?
LGBT people have been able to serve openly in the US Military as of 2011. However, as of 2017 (the date of this answer), the issue of transgender people being suddenly banned by Donald Trump has come up, and is not fully resolved yet.
Yes. In January, 2013, the military lifted the ban for women in combat roles, but many women served in combat before the ban was formally lifted. According to the Associated Press, women will be able to start training as Army Rangers in mid-2015 and women will be able to start training as Navy SEALs in mid-2016.