Revealed Top Deck and Burst

This is a two part question.
To start, I would like to reference a specific combo that has been used quite frequently. Tobi N-1014 and Karin N-980. If I remember correctly, people would also use Decoding the Message N-821 in addition to the previous two. With the way that mission is worded using the newer style of separating cost and effect, doesn't the effect imply "in that case" just like the cost implies "you can"? And if so, would Karin conflict with the mission so as to make it completely ineffective? Since to get the "in that case" effect, one has to fully apply the cost. At least, that is my understanding.
This ties into the second part concerning Burst. The way that the Burst effect reads, I can't tell if "in that case" is directed at the line before or the actual cost. I guess what I'm asking is: Can one use Burst even when the top card of the deck is revealed?
Thanks in advance.