Am I free to tune down and up to different tunings whenever I want? Will it mess up my guitar because of the change of pressure and stuff?
won't mess up the guitar, the strings might go out of tune more if you constantly change the tuning though.
Gibson SG Standard + 18volt EMG-81 & 85
Mesa/Boogie Mark IV + Recto 2x12
Keeley Modded BD-2
Vox V847a
Quote by one vision
Bureaucrats gonna crat.

Recognised by the Official EG/GG&A Who To Listen To List 2008
if you do a drastic change you might have to adjust the tension springs in the back. it also depends on what kind of bridge you have too but you should be alright if you are tuning down one or two steps. but if you want to play something like korn or slipknot you might need to do some adjusting.
"im not going to call somebody a dwarf unless they have direct possesion of a battle-axe."

"curiosity killed your mom!"