Any advice on simple trim on front and side door to fill the depth gap.
(https://i612.photobucket.com/albums/tt208/rrtravelpics/2011-05-08122525.jpg)
What's the depth? Paint or stain?
That calls for an "extension jamb" I usually make them out of 1x pine ripped to fit the depth. I can often chuck up 16 or 20d finish casing nails and spin them in thru the edge into the door jamb. On a door I try to get the jambs the correct depth for the wall thickness if possible. The correct way to extend a door is on the outside, bringing the hinge knuckles into correct alignment with the interior wall surface. If there is an intersecting wall on the hinge side then it works to E jamb on the interior because the door does not then need to open fully. If there is not a wall behind the hinge side then you should rehang it correctly. At some point someone will fling the door open and it will put a hurting on the hinges and jamb.