Hi Granddaddy,
First thing, Qimage remembers the last PRINT crop you used for an image at a particular size, so no worries there. 

If you are  talking about actual saved "Jobs", then you cannot combine them directly as you recall.
However you can combine saved Sessions.
Here is what I would do:
Recall each job in turn and remove the images you do not require, then save as a separately named Session.
I assume all the printer settings would be the same for each job you had saved so they will  be in place.
Now recall each Session in turn and when asked, choose "Append", in that way each set of images will be added to the queue. You can then save the lot as a new Job or Session.
I like to use Sessions because of this sort of flexibility and it allows me to change the paper type late in the game if necessary.
Terry.

It's horses for courses. Sometimes it is important to save the whole thing but when the is a likelihood of changing images in the queue or the printer set up, then saved sessions are more useful.
Terry

Done 
Terry