Can a gay man love a woman?
Yes, the degree in which a gay man may love the woman may vary, but yes a gay man can love a woman just like any other person. I fell in love with a Woman and was about to propose, unfortunately (or maybe fortunately, depending on how you look at it) it didn't happen. I still loved her for years later and today still hold special feelings for her, in the long run it was better that I didn't marry her.
Being a Gay Man doesn't mean you can't fall in love with the opposite sex, you can't "make" your heart fall in or out of love, it happens regardless. Though in all honesty it is less common for a Gay Man to fall in LOVE with a woman, but we still love those we love.
No. A gay man is, by definition, a man who is attracted to other men. A butch woman, no matter how butch, is still a woman. However, If there is a man who seems gay and is attracted to a butch woman, he would be considered bisexual, and a bisexual or straight man could definitely be attracted to a butch woman.