Carry without safety

So I'm a pretty new carrier (roughly 1 month), and I'm comfortable carrying with one in the chamber but not safety off yet, BUT, I want to be. For reference, I carry an M&P shield 9mm in a full kydex Concealment Express holster at 4 o'clock. I guess I need experience and peace of mind.When its in the holster, can any pressure/weight possibly engage the trigger? (Im only 123 pounds, small frame).Can a kydex holster retention be "too" loose that it can increase possibility of negligent discharge? (I keep my holster just loose enough that if I shake it upside down hard it can fall out. This is so when I draw it doesnt pull my pants up too much).Are there any specific movements or other such things I should know or worry about while carrying 4 o'clock?Thank you for tips or constructive criticism on my journey of concealed carry. via /r/CCW http://bit.ly/2GQhbRh