I recently saw Emma and then hurried to buy all the manga as well...I love it;)
Here are my theories (answers to your questions...)
Yes, I think Richard and Aurelia love each other very much, they really do. I wouldn't be surprised if they both were thinking "Wow, I just really want to be back with you sooo much, but is it what you really want?" I am sure that Richard doesn't resent Aurelia as his wife for not being able to keep up with all the social duties because he loves her so much, but I am sure that part of him is upset that she was unable to. I think he just feels badly that this was, unfortunately, the best decision that could have been made for everyone in the long run. This might be why Richard is so hard on William when it comes to Emma. Never once does Richard tell William that his feelings are unreasonable, just the idea of marriage to Emma. Richard knows exactly how William feels because their situations are very similar. Both fell in love with women that were not perfectly cut out for society life, and Aurelia, though she was from the nobility, obviously did not care much for the lifestyle. This at the time, however, rather than sending a red flag to Richard, enchanted him and he fell for her, just like William did with Emma. I am sure Aurelia and Richard wrote letters and visited each other as well. I would be quite surprised if Richard didn't take a few days off here and there to go up to Haworth and spend time with her...or he might have moved to the countryside after his retirement. (awwwww, now I just went all sappy)

William does need to be whapped. A few times actually. I agree

Sorry this was long. Just wanted to spread the Emma love.