Thanks for the nice review!
Concerning international applicants, if we are strongly interested, we arrange a phone interview. Unless the international applicants are already in the US, it is impossible for us to get them into the country as quickly as we would have to to attend the open house. And since we can't arrange for visas in that time frame, it's a little unfair to only invite the applicants who are in the US, and can travel here without visa issues. That said, if you are in Boston during February or early March, and are being considered, we generally try to accomodate you for a visit. But make sure to give us plenty of notice - this time of year is extremely busy for all of us.