Lmfao that is just ridiculous xD I wouldn’t charge people for asking questions. How would I even go about doing that? I enjoy answering questions. I just don’t have the post space on my blog or the time to answer so many. But I am not going to start charging for them.
You should consider charging 25 or 50 cents a message. It isn't much to the askers, but it would add up! Your tumblr is so much fun it is worth it. Also, thought the idea of someone a few days back for you to have guest posters is great. People without sites could share their progress etc.