'Well done' can also be translated as 'hyvin tehty'
That's what I wrote and it was marked wrong. I reported it. You should, too.
Is todella incorrect here for really?
Yep! Todella and tosi mean the same thing
What is the difference between, or how do I determine when to use, 'todella' vs. 'tosi'?
Todella is more of a kirjakieli word (writen language. Its in books, but is spoken on the news for example), while tosi is more puhekieli (spoken, more informal language), but they mean the same thing.
Does hyvä followed by a name also mean dear?