1. "It's worth waiting for" or "It's worth the wait?"-- Both are OK. 2. The award for second place goes to Timothy in Grade 3. 3. I should have helped him. -- OK
4. I hope that you enjoyed the trip.-- A past trip. ("will enjoy" -- A future trip)
5. I wish i could or i wish i would? If i were you, I will or I would or I could?-- All a