Can I edit auto-complete dictionary? Currently my LG G2 Swype-style input with the LG keyboard gives me boneheaded suggestions like tho for to (and actually prefers them). I see elsewhere that user dictionary editing is not available, but some of these entries are five years old already. Any progress on this front?
You can change the words in the user dictionary by going to Settings > Language and Keyboard > User dictionary. From here you can edit as you wish. There is another way mentioned here that may be easier for you: How to remove misspelled words from your Android Dictionary

"Maybe this is more obvious to everyone else, but the dictionary is accessible from the speech-to-text button. The gear icon actually means something! Long-press the microphone to get to the Touch Input settings menu. From there, click User Dictionary and edit out all your "well, crap, I did it again!!!" entries. You can also add entries (at the top), you can long-press an entry to edit, or click the red X to delete."

This is a good article that I have read before. Hope it helps!