I'm in Beijing in last week of Mar 17 and planning to take airport express to reach hotel in Guomao.

1. You are suggested to keep CNY150 - CNY200 in the card. Don't worry, the money can be refunded if you don't use it up.

2. The ordinary card is only available at local. However, there is another card called 'BJ-Tianjin Smart Card' can be used in the pariticular bus lines in these two cities but not metro at present.

You can apply for this card at the branches of ordinary card. I'll list a branch near your hotel:
The Metro Line 10, Guomao Station, Branch at the Exit E