If my throat feels a little scratchy after singing, is this a sign of straining?  I'd like to avoid this feeling but I am not sure what to address.  

Hi Chris, that's a great thing to be aware of! I'd pay attention to any specific exercises where you're feeling strain/pain and feel free to modify them (singing on something semi-closed like a lip trill or NG sound, for example). If it cannot be sung comfortably at all, you can sing 1 octave lower or drop out until the range becomes doable. Things that tend to tax the voice are singing too high, too loud, for too long. Some discomfort when exercising a new part of your range (or singing in a new way) can be normal and is good feedback for you to note, make adjustments, and see how those work.