I am newbee in facebook and i have few questions regarding the game that i am building which has to retrieve client's friends once he enters his facebook id and password. The game will ask user to enter his password and id and then it will import all the contact list and save in the game server database. (This way next time when he require to invite any other gamer we will send the other person an invitation on his email) but here is the below scenarios that i am unable to solve yet and required experience suggestion.
1) Saving his password for future friend retrieval is very bad idea , what would be the best technique to retrieve his all friends by not asking every time facebook password to synchronize his contact list on our server?
2) The mobile game is not available on web , but still we want to connect with facebook to show scoring on the gamer's facebook wall. But Facebook require to create an APP and provide a hosting url link , i am wondering how is this possible with the mobile APP.. does it mean i must create a simple web page on hosting and then communicate with ajax ???