actually side stitches are somewhat of a mystery to the medical establishment. it's just a mechanism that tells your body to slow down, it's got nothing do to insufficient breathing.
as far as running faster, I was at 21 minutes last year. Now I'm a sub 18. I got up to 50 miles a week during the summer. all of them pretty slow, first at a steady 9 minute pace, now I do them at 7:30. Don't do too many max effort workouts, because they'll break you down. I got these running techniques from Arthurs Lyliard's (sp?) Running to the Top. Be careful though, listen to your body. I got shinsplints that took me off running for like 2 months at the beginning of September. I kept trying to get back to running too early. Now I'm just really getting back in the hang off it (12 miles this week). I did stairclimbers for like 2 hours a day when I couldn't run.
Try to be able to run a steady 10 miles at whatever pace you're comfortable with. Then add speed workouts.
Use this calculator:
http://www.mcmillanrunning.com/Running University/Article 1/calculator2.htm
As far as pullups, I don't follow any plan. I just do as many as I can, but never a max set. Rope climbing really helps too.
I also swim, 60 x 25 yards 3 times a week to balance myself out. Frontcrawl ,breaststroke, sidestroke, inverted breast, backstroke. I can't do a butterfly though.