Dear DisgruntledMonotheist,
You have raised some interesting and relevant questions. For anyone trying to properly understand Hinduism, unfortunately, is a daunting endeavor. The main hurdle for someone who grew up with "mono" ideas, is the depth and diversity in Hinduism, of ideas, philosophies, practices, customs and rituals - there is infinite variety to choose from. Better yet, you don't have to choose any one - you are free to explore them all. You are completely free - which is quite uncomfortable actually - because we are so used to being "controlled". The second major hurdle is discarding the biased opinions that influence us and which keeps us from even trying to understand the basic ideas. We shall discuss the details later if you want to continue this further.
For now let us look at some of your questions, .
1. Is it welcoming to people who are not of Indian descent? Particularly, to people of African descent? (I'm an African American female).
Absolutely. Not only be just welcomed, but if you are "the one", Hindus would even worship you as an incarnation of Goddess. Example:
A Jewish Goddess from France, The Mother: Mirra Alfassa (see Wikipedia)
Also, meet Amma this year: see amma(dot)org tours page.
As mentioned earlier there are some African Hindus in the ISKCON tradition.
Ricky Williams of the Miami Dolphins is well-known African-American Hindu (see Wikipedia).
There is Laetoli le "Kali" Baaba - google him and see his youtube videos also.
In those videos you can see that Hindus come in all colors. There are Mongoloid (Indo-Chin) Hindus, African Hindus, White Hindus etc. This is a partial list of people who have converted to Hinduism:
Wikipedia - List_of_converts_to_Hinduism
Wikipedia - Category:Converts to Hinduism
2. How does the religion treat "liberal" ideals such as women's rights and equality, and gay rights?
Sexuality: Hindu philosophy and culture completely embraces Nature in all its diversity, including sexual diversity. Wikipedia - Hinduism_and_homosexuality
Women: As mentioned earlier several women have authored sacred scriptures since the very ancient times. About the status of women this should give an idea - out of the 8 philosophers on this page 4 were women: Wikipedia - Category:Ancient_Indian_philosophers,
Women_in_Hinduism#Female_gurus_and_saints,
List_of_female_mystics#Hinduism,
Legal_rights_of_women_in_history#Hindu_in_Ancient_India
Kamat(dot)com - Kamat's Potpourri : Women of India
Certainly, the phenomenon like Amma and The Mother are pretty much impossible in cultures where an Abrahamic religion is dominant.
Sorry, I am not able to post the urls for the above references since I just joined this forum.
I will respond to the remaining questions soon. Please take some time to look at the above details. Have a great day!