1. There are many possible reasons people site as to why Buddha hesitated in allowing Mahapajapati to join the sangha. Can you think what any of them might be?
I would think that because of the times in which the Buddha lived were structurally based around a heavily male dominated society. That is, men were considered more important, smarter, entitled, or even superior to women. I believe its one of those things that people were brought up to believe, and the Buddha may have had concerns about how others would view this. Obviously there could have been any other number of reasons such as, he might be concerned about the lust factor between men and women as well. Unfortunately those stigmas about people still hold true today. However, I do believe that those barriers have been broken significantly in many countries.
2. Does the Thai sangha benefit by keeping women out? Why or why not?
I think that when you do not include someone who could be a potential benefit to a group then you are missing out - whether it is a woman or man. I understand that people have traditions, rules, and other things that can upset a delicate balance of crossing one path or another – but to me it does not make sense to disallow a person because of their sex when they could benefit a sangha with their wisdom, experiences, and compassion.
3. What do you think the Buddha would say today if he were here to give advice to monks and nuns?
I would hope the Buddha would say something like he always would. Be mindful, treat each others with respect, and be compassionate to all sentient beings. I would also hope he would let them know that no matter who they are, they have to potential to become enlightened and that each monk and nun are the same, both capable of all the precepts, teachings, and helping others to attain enlightenment.