The parents are executed first, the sub filter afterwards.
Yes, you can copy the entire tree, by selecting the parent message and pressing <Ctrl><Shift><C> or by means of the right mouse button and select 'Copy tree', though I don't know whether that's available yet in the public release (3.0) or whether that's still a beta feature. (I recall a time it wasn't possible)
I'm just a user of The Bat! I don't work for Ritlabs.