Since your post was written quite a time ago i guess you're already at a higher level now.
However, if you're capable in 2-manning trash in RFK you probably will also be able to clear trash in Scarlet Monastery - if you take it easy you'll probably pull a maximum of 3-4 elites. In Library, as far as i remember, mobs don't hit that hard so this should be doable. In Armory you'll get disarmed a lot and the Myrmidons enrage when reaching lower hp. Cathedral also offers the possibility of smaller pulls which would be perfectly fine for a 2 man team imho
I leveled my team (currently 10x80) 99.9% via dungeon grinding - which was slower but also yielded a lot of gold (selling greys, disenchanting etc).
The only questing i did was to reach friendly reputation (solo questing the characters there) and Zul'Drak Arena (was done at ~3 am since i really try to avoid being seen multiboxing in the open world)...