First...
The Sentence diagrammer tool it really really smooth...it works just fantastic...
The very few things I could see needed improvement have been mentioned but this one...hence this suggestion:
When you multiple-select words, and then get them out of alignment, they are very hard to get back to alignment; either horizontally but mostly vertically...and it seems like I never can.
Could we have a way to multiple select words and choose "realign horizontally and vertically" or something like that?