2. Somewhat...but not really. Your best bet is to keep doing more riding. You can try doing leg lifts and scissor leg lifts. Also, sit-ups or crunches.
3. Lunges and split leg stretches (or the splits, if you are more flexible than me :P ). Also, body twists and ab stretches. My best recommendation would be to get a basic yoga work-out dvd, like Yoga for Dummies or something. The basic routine on that dvd is awesome if you are sore.