Thread Necro but it may be relevant to XP starved F2P
You can, and its allot of fun
What you can and cant do ?
What You Can Do
Do open area quests to some extent
Kill count sub Quests
Quests with things to click in the open world
Get tons of XP !
What You Can't Do
Enter any instance class or otherwise
Some quests, even out of instance won't work properly but most do
So in short travel the planet as an ops group with defined sub groups kill count's are separated buy the subgroups in an ops frame, so stick together in packs of 4 or 8 and mark the leader of each pack
High spawn areas and heroic area missions net a lot of xp. Chaotic but fun.. things exploding everywhere
Split up into groups of 2,3 or 4 for the instances and get back into the ops when they are done
... yes try it on the Black hole kill quests!
Tip: Have the designates leader set the ops group to "open" then players can type /join (Leader Name Here) as they finish there class quests.