Water in my liquid or worn out coils?

[greek mule]

These juices are supposed to be 80 percent VG, but they are very thin. This is another reason I thought water might have leaked into the bottles.

You'r welcome!Some high vg e-liquids contain water,it should be written on bottle ingredients.

When was the last time you changed the coil? A "sizzling noise" when you fire the mods, and "almost no flavor and hardly any vapor" could just be a gunked up coil or gunked up wick.

Correct.If your coils /cotton look junked,re-wick after you dry burn and rinse under the tap the coil/coil.