New user looking for a way to create an editable path in first-person.

I've been banging my head against the wall trying to get HOTWeen and iTween to work for me, but am having no luck.

I've learned how to create a path in first-person using the Animation tool(CTRL+SHIFT+W to plot keyframes along the way) but would like to be able to then edit the spline afterword, visually, with transform handles.

Is there a way to get the best of both worlds? I am planning a very complicated flight path and think I'd save tons of time if I could inch my way through in first-person rather than plotting and adjusting dozens of nodes on a spline from the get go.

Thanks for any ideas!