Regardless of where the thrust is applied the Earth's escape velocity remains the same. If you don't achieve that then you don't get into orbit. Thus your contention is not only wrong it's ridiculous. If the exhaust is at the back end then the "lifting" is from the back end. Absolute crap. If there's no reaction then there's no movement. If there's movement then there's a reaction. No. You've already been given some reasons (one of my first posts in this thread) why thrust applied at the "front end" (which isn't a feature of your system anyway) is less efficient than that at the back. If it's less efficient then you need more thrust - larger/ more powerful engines. Because whatever "details" you have are predicated entirely on ignorance and wishful thinking.