Using RSS feeds for member updates?

Hello,

I am a web designer and new to wordpress. I am thinking about creating a site that has multiple categories where users can post services they have for other users to see. Can I handle this through multiple RSS feeds on one site? For example I would have users subscribe to whichever categories they are interested in and then would receive daily updates of what others have posted in that category.

Second question, can an RSS feed be sent via e-mail to the users who subscribe?

This is a little new to me and I’m not a programming guru, but I think I could figure it out if it’s possible. I’ve done a little research and it seems potentially possible but I thought posting with the experts would be the quickest way to find out if it is. TIA!