As far as the rolling goes, that flexibility can definitely be developed. I'd start practicing the rolling technique with simple two-string sweeps. Start it on the high B and E strings. You're going to want to lay your index finger across the A on the 5th fret of the E string and the E on the 5th fret of the B string. The pattern you're going to play is:
E|5-5----5-5----
B|---5-5----5-5-
Picking pattern: D,U,U,D,D,U,U,D
(sorry it looks not-so-neat, I don't know how to embed a powertab image or something like that)
etc. over and over. Just like any technique excercise, do it as slow as you need to do it in order to do it cleanly. By doing only two strings, you'll be able to focus on the rolling in your left hand without having to pay much mind to your picking hand. You're going to want the part of your finger where you normally fret on the B string and then you'll arch it down to get the E string as needed. The motion itself should come mostly from the joints in the fingers, but the wrist should help. The biggest thing is making sure you arch it enough to mute the string you aren't playing at the time so you've gotta be very self-critical when you're doing it slow and make sure you're doing that from the start. It'll vary for everyone because everyone has differently sized fingers and whatnot, but by paying real close attention you'll be able to find the amount of motion (and where the motion comes from) that works best for you. I should also mention that the 2-string sweeps can be a really cool effect to use in your playing here and there because it's easy to get them REALLY fast. Check out some George Bellas...he does that a bit.
After you've got that down with your index finger, do the same with all of your fingers using the 2-string pattern. Then, apply the same thing to each string group. Then, as logic would follow, expand the concept to 3 strings and practice that with each finger. Once you've got the rolling technique down solid on 3 strings, you'll be in pretty good shape. I would reccomend being able to do it on 4, but it's not as common to do that in an actual piece of music. Then again, it's better to be able to do something and not need it than it is to need to do something and not have it.
The articulation will improve drastically by just cleaning up the left hand, but paying some extra attention to the right hand and experimenting with how heavy your pick attack is might be worth playing around with too. I while back, I made a powertab file that I would play along with once a day that had all kinds of sweeping patterns and excerpts from different songs, etc. I don't know if I transferred the file when I got my current laptop, but if I can find it I'll upload it for you.
In the meantime, see if you can't find some Frank Gambale books/videos. Here's a powertab file of the examples from his "speed picking" video
http://powertabs.net/tablature.php?id=21365 . Lots of great stuff in there.
As far as the finger flexibility, I'd work that independantly from the sweeping for now. If you don't already use/know the 3 note per string scale patterns, start using those as they will force you to stretch a little bit beyond box patterns (there are exampls of the 3 nps patterns in the gambale examples above). Here's another exercise that does wonders for finger stretching/flexibility:
(on any string)
|-1-2-3-4-1-2-3-5-1-2-4-5-1-3-4-5-1-3-4-6-1-3-5-6-1-4-5-6
The catch is that you have to keep each finger planted down as the next finger reaches for it's fret. Not many people can comfortably do this from the 1st fret (myself included) so there's no shame whatsoever in moving it up a couple positions. And don't push yourself to the point of injury with that one. I know that's probably stating the obvious, but some people can't distinguish from the healthy pain that means that you are working the muscles/tendons and the bad pain that means you are hurting them.
Hopefully some of that helps. I'm not so good at explaining technique-based concepts via typing so if anything starts to resemble senseless babble, it just might be
I'll definitely try to find some time to practice these techniques. Do you baby sit as well? Ha!
