2 main reasons of fatalities
In fact the two main reasons are
(1) taking off when you should have stayed on the ground
(2) pressing on with Plan A long after a switch to Plan B was called for.
Included in the above are all the usual things, like
do not fly into cloud
do not run out of fuel
and so on and so on.
All of which basically means carry on taking seriously all the stuff you were taught.
Look at the statistics. "Loss of control", which you appear to be worried about, is a very small cause of crashes. Leaving out, that is, people who lose control when they fly into cloud they aren't qualified to fly in - but the solution to that one isn't adding widgets to the aircraft ... it's simply refraining from flying into cloud ... which in turn quite often simply means staying on the ground on days when the weather means you've got no business to go flying.
One thing I've found helpful which no instructor ever told me: when you offer someone a ride, if it's in summer you tell them that there's a 50/50 chance of it being cancelled due to bad weather, and if it's in winter you tell them that it's four to one on being cancelled because of bad weather, and you tell them that you might decide to cancel
after they've taken the trouble to travel to the airport. That way there's no pressure from passengers to go flying when you shouldn't.