These have already been said, but it's worth emphasizing them:
(1) Daniel Jackson wanted nothing more than to go to Atlantis. He practically gave up being ascended for the Lost City. And after all the talk, all the failed attempts to get there (Prometheus Unbound, Avalon) he spends one episode there (The Pegasus Project) and then goes home. He should have been a far more regular presence once contact with Earth was achieved.
(2) They should not have contacted Earth so soon, however. Limited supplies, limited crew. That was a great premise. It made for heightened drama in the first season. A people like the Genii were suddenly a threat. The Wraith were SERIOUS. Once they get contact with Earth (and the ridiculous amount of ships that come with) all that was deflated.
(3) Explore the city. Isn't it the lost city of the ancients? Why are they spending their time going to Renaissance Fairs?