I just want to know if it is ok to hose down my engine bay. Would it just be better to clean it by hand? Thanks in advance!

 

You can hose it down without problems. But make sure that it's cold. Do not drive anywhere and hose it down when its warm/hot. Let it sit overnight or at least for a few horus after driving.

You can cover your alternator with plastic if you want and just hose way.

Good luck , Bob