Pretty good port! It was a bit on the loud side, but it's nothing that a small global volume adjustment couldn't fix.
Also, the vibrato in the bass channel is almost inaudible because of the fast release of the instrument, and because the second byte in $DE is much higher than the second, which results in almost no vibrato at all. This is very small, so it's not a big deal.
Well of course you can't. Major Flare is telling you to change the tempo before inserting it into your own hack.
I already did that. What must I do, now?
Well, what you must do is simple. Enjoy it at your own leisure. Nothing more is needed. Remember, just because we submit things it does not mean that they are to be used as they are. You are free to adapt them to your likes and needs.