Anywhere that off camber situations are encountered will benefit from LCG. A tire in the air is better than all four in the air.
There are other ways to get more flex than MC fenders. There are DIY highlining threads are out to allow for more uptravel. Tube fenders or MCE flat fenders will gain a little more too.
Keep in mind that you also have to pay attention to your shocks. You don't want those guys bottoming out on you if you want them to last. For more gains in flex look into shock tower mods with F 150 brackets or tube brackets.
For clearance on the belly pan, yes a 5" lift with belly up pan will be 2" higher than a 3" lift given the same pan and tires but you can work with it. The important thing is to make the bottom as flat as possible (get rid of the shovel) and picking the right line so you will be fine sliding over stuff.