Poor management?

I love this show but it seems that charecters come in and out of it in really strange and intolerable ways:
Geoffrey: (End of S1) everyone agrees that Geoffrey would be a good addition to the group although him and josh are no longer dating.
(First episode of S2) *clicks fingers* Gone!
(Further along in S2) reintroduced-leaves again
Claire: (end of S1) in love with tom.
(Start of S2) *clicks fingers* gone!
(Mid-season 2) comes back from
germany deeply enjoys time back
(Three quarts through) needs to leave back to Germany although she has no friends there and doesnt speak german to find herself although she is clearly not lost.

There are alot of other holes in the script as well.