Grainy photos and troubles in macro

[BlueAbyss]

My Panasonic Lumix FZ8 has Aperature Priority and Shutter Priority (as well as Program Auto Exposure, Manual Exposure, Intelligent ISO, and Simple), while in either of these modes you can adjust the setting that has priority and the other (either shutter speed or F-stop) adjust accordingly to give you the proper exposure (if possible). It will over or under-expose if you push the settings above or below a certain threshold, in either of these settings, but I can adjust the exposure also in all of my settings +/- 2 stops, to somewhat negate this effect.