2. No. At 4 weeks lagering there should still be plenty of yeast in suspension for carbonation.
I said maybe on 1. because it depends on if you've done a sufficient primary. Assuming you have, then yes.
FWIW, I like about 3 weeks in the primary, the 4th week being cooled down to lagering temps couple degrees a day. Once its at my lagering temp then I will rack.
"If you do it right, brewing is about ideas. A big impression can be made with brute force, but sometimes a whisper speaks louder than a shout." - Randy Mosher
Primary: Citrus Wheat Experiment/WLP029 & WYEAST 1056