Answers to your questions.
1. No as long as you have a medical its all that really matters, When it comes to airline medicals all their really looking for is possible medical reasons why you may prematurely leave the company and wont be able to fulfill your contract.. Because they have paid for your training, and want service in return
2. Yes do you medical as soon as possible. If you cannnot become a pilot, you would want to know now!!!! Before you spend thousands... Once passing a medical, make sure you take care of yourself, for a long happy career in aviation