Acording to my experience in multiple JDAM drops, you don't necessary need to lase the target before you make your markpoints. If you don't lase make sure, that you are pointing to the bottom of the target and not the top. Usually if you are in FLIR mode in the TGP and you use POINT instead of AREA, and lock the tarket with the TGP will give you a good markpoint for hitting the target.
Also I find unnecessary to make an entire new flightplan for a multiple JDAM drop. Plan ahead, and mark your targets accoring to your final attack HDG. If you do so you won't need to mess with the CDU. Also you can use your HOTAS buttons (I think it is TMS up/down) to switch trough STRPs, if you make them a SOI. I
If you have any fruther questions feel free to write me! :)