Hi Tiddys we very well may be what you are looking for.
We are a mature guild that enjoys running operations in a casual way. We have designated teams that are progression oriented and then we have Open free for all runs where we take any and all and have some fun clearing bosses. Obviously the hardest content is reserved for our progression teams because they require coordination and thorough understandings of the mechanics. But any member is free to join a team that has an open spot.
Our recruitment post is here: http://www.swtor.com/community/showthread.php?t=556195
You may apply at www.omegaknights.com