@Ketsuekiame: Thank you! I went through and changed the names so they all fit one style, and I also made the other changes you recommended.
@tinstaafl: Hmm, I didn't even think about doing it that way. As far as I can tell
output += ToBinary((int)input[i]); gets rid of my need for the ASCII conversion for loop while concatenating each 8 bit output into a single output, and
(int)input[i] is what leverages the implicit cast, right? Thank you!