1: Leave it for more than a year in the training pot if you want to help it thicken faster
2: You can start wire training now but not major wiring, i mean you can only wire the trunk
3: no, don't cut the leaves as bigger the better for now, a tree will always thicken faster if left unpruned.
4:no, you might even want to plant it in a bigger but shallower pot, bonsai pots restrict the growth of the roots which in it's turn reduces the growth of the trunk
5: Depends on the species. On a conifer, it's better to start these 2 at aproximately the same time due to lack of backbudding, but on decidous or tropicals you should take care of trunk thickening first and then start developing branches.
Also remember that you should try to give it the best conditions possible(lots of sunlight, warm temperatures, adequate watering, and regular fertilizing)
Take a read at this:
http://bonsai-bci.com/species/ficus.html
http://www.bonsai4me.com/SpeciesGuide/Ficus.html