I can’t answer the second one, but for the first one, I’d generally say you’d have to try to have the commission done in 2 weeks for a drawing.

Hmm...commission time depends mostly on how long you yourself feel it would take to finish a commission piece when mixed with your schedule. It can vary, but should typically take no more than 2 weeks unless otherwise stated.

For pricing...that's a tough call. I guess the best thing to do is figure out a price point you yourself feel they should cost. If they are not selling well after awhile, consider a slight price drop. If commissions are flowing in quickly, consider increasing the price after awhile, and if things are fairly stable, not slow or fast, keep it at that level to gauge interest and eventually raise the price down the line as you become more known.
That's what I think on it, but I think it would be best to ask another artist who does commissions on the best practices for setting prices.

Often, there is not an actual deadline, but it is usually considered good to complete the artwork within a month, unless it is an elaborate artwork.

For price, it is best to make a price based on how much time & effort it takes for you to complete the image on average, but it is completely up to you to decide your final prices.

1: After a customer pays me money, I will respond with a sketch within 1 week, and a finished picture within 2 weeks. I think this is typical.

2: For an amateur artist, you should think about how long it takes you to draw a picture, and charge between $10-$20 for each hour. Most pictures take me about 3 hours to draw. So, I charge $60. Professional artists will charge closer to $30-$80 for each hour.