Try to go get flag with a player that can carry flag (pref 1,3k+ resi or so), a healer and you. Escort them, tell them to wait up if you get behind. Once you've reached your own Flagroom and the oposing faction got your flag, go back and retrieve it. Tell others to defend the FC and possibly ask 1 dpsclass to join you so he can actually click the flag to return it. So you can just nuke at range.