1. Don't be frustrated with the delay. Just like any other business they move at the speed dictated by the staffing situation. If they are very short on people things happen fast. If there is not much turn over - they will take their time.
2. Of course it'll help. Do a good job so your supervisors could give you good recommendations. When time comes don't be shy to ask for them.

It is a great company.
All the best.