Your powerpoint moves awfully fast and does not have an audio track so it's very hard to follow. Adding audio after you do an animation is a backwards way to do this kind of project.
If you have never used AE before expect to spend at least a couple of days learning how it works. You can make presentations in AE for sure, but you need to do a little more work on the concept to make it effective.
If you like what you did in powerpoint and you are only concerned with the quality of the render then you should be able to render your Powerpoint to a better codec. If you spent 'way too much time' in powerpoint, expect to spend even more recreating that project in AE. AE is powerful, but creating a project where you have to animate everything by hand or by animation preset is not nearly as fast as creating presentations in Power Point.