Its hard to tell from the pics,but the inverse taper could just look that way because of the twist in the trunk,i would be worried about inverse taper at the very top of the tree where it was choped.Its hard to see,but i think its a whorl of branches there,if so,eventually you will need to lose some of those branches,you might even want to chop all that top off eventually when you get some buds down lower.You need to decide now,what you want the finished tree to look like,height and style,then make a plan.This tree is very young and as mentioned will need a few years to grow,for faster growth it might be a good idea to grow the tree in the ground if possible,check out Brents articles at evergreengardenworks,There is much to learn about training pinesfor now focus on keeping the tree healthy,and the rest will come in time,dont rush anything,all the nice pine bonsai have taken many years to get that way,its not going to happen in a growing season.Good luck with your first pine.