Welcome to the CS forum.
Dry ribs could be the result of several factors.
Rub - a medium to high salt content rub will draw moisture if applied for more than several hours. Try applying rub within 30 minutes of smoking and see if that makes a difference.
Meat - baby backs tend to be more forgiving vs SL spares. A 2.5# rack of BB's is a good size to start with. When selecting ribs, look for meat, striated with fat, covering the bones. A rack with little or no meat over the bones (shiners) tend to be dryer.
Time and temp - while you don't mention a size, 3 hrs @ 225 seems like too little time. "Very tiny pink center" really doesn't tell you much. Try using a round toothpick, inserted cleanly between the bones to test the tenderness of the meat. A properly cooked rack of ribs (either type) will let you penetrate the meat, with little resistance.
Apple juice - nothing wrong with spritzing but every time you open the door, you're extending the cook time.
Suggestion - next time around try a rack of BB's in the 2.25-2.50# weight range. Rub 'em just before you load the 008 and let 'em go for 4 hrs. No peekin
At 4 hrs try the toothpick test.
Let us know how they turn out.