I created a number of snapshots of different edits for comparison and saved the .psd file. The next time I opened it all of the snapshots were gone. Is this normal or do I need to configure something differently?
#1
This is normal, working as designed. Snapshots are not saved with the file. Info from help under "About the History palette" --
Once you close and reopen the document, all states and snapshots from the last working session are cleared from the palette.
#2
You could copy each snapshot onto a layer and hide them, as a workaround.
#3