Well Ficus are notorious for dropping their leaves when they are moved. Its not so much that they are picky, but rather that the new leaves that grow back will be acclimated to the area in which they grow, so if they are moved again, they will need new leaves for the new area. Other trees don't drop their leaves as easily, but they can still have difficulty when moved often because they are unable to properly acclimate themselves to the new area and stick with it; they have to keep changing. Fruit trees will not be an exception to this.
Depending on the differences between the areas you put them (elevation from your roof to your lawn shouldn;t make a big difference unless you roof is really high up there. Its the actual weather conditions that matter), it may be fine. If all the areas have about the same sun/shade, heat, wind, etc then it shouldn't cause a problem. But if you roof is really hot and kind of windy, and then you put it on your lawn where its shady and still, and then back up on your roof, your trees might get a little mad. Though most trees won't drop their leavs like a ficus will (unless the chages are more drastic such as from sunny and hot outside to low light, cool and drafty inside), they still may not like the change. It will likely weaken their resistance to disease ad pests as well as make figuring out things like a watering schedule difficult.
There are some exceptions where people will shock a tree into doing something (such as flowering) however this is not a process that is done every couple of weeks or so, but rather normally only once a season at most, and should be done very carefully, because too much shock will kill the tree instead of causing the desired effect.
Your trees will probably be happiest if you just pick a place and keep them there. It will be a lot less stress for them. If you want to show them off, the you can always move them for a few days, but then put them back, or keep them in a suitable place where they can be shown off, and leave them there. Your trees will thank you for it.