No damage. No harm done. The VTA effects people are talking about, bloated bass vs too bright, are gross. In other words that's what you hear when its way way off one way or the other. The closer you get to perfect the more you have to start listening for finer details. Unfortunately you'll never get the chance because the VTA adjustment I'm talking about is tiny fractions of a millimeter while your arm requires changing washers. The washers are fine for getting you into the ballpark. Perfectly dialed in VTA would have you measuring washers with calipers and the time and trouble just won't be worth it.
The easiest method with your setup is to look closely at the cartridge while playing a record. Almost always you want the cartridge to be either perfectly flat and parallel with the record, or very very slightly tipped down at the back. There's a very small flat area on the bottom of your cartridge. Make sure that is parallel to the top (where it fastens to the headshell) and then use the washer that gets the bottom of the cartridge flat or very very slightly tipped down at the back.
The easiest method with your setup is to look closely at the cartridge while playing a record. Almost always you want the cartridge to be either perfectly flat and parallel with the record, or very very slightly tipped down at the back. There's a very small flat area on the bottom of your cartridge. Make sure that is parallel to the top (where it fastens to the headshell) and then use the washer that gets the bottom of the cartridge flat or very very slightly tipped down at the back.