Dropping a motor in- any last tips or advice?

Interesting, I've never tried having the back of the car raised and the front lowered.

having to constantly hold an engine in one position when it wants to spring into a funny angle while raising or lowering the hoist can get annoying really fast.

If running a single chain diagonally, I would suggest having a horizontal pivot point above the hook like what is shown in this example

http://blog.mr2ev.com/engine-removal-day-3/

This allows the engine to be rotated while remaining horizontal and neutrally balanced.