It does have a keyboard emulator as part of the software and it seems to work just fine. I included some documentation with the download, according to the documentation some of the ATR Mega Images may require a real DC keyboard but I did not include any of those in the archives, just single .ATR files.
I am not sure on burning on a Mac. In Disc Juggler I use the following setting for all my Dreamcast burns (including this one) Mode/2, Block 2048, Raw Write, Add Post Gap, 8X Write Speed, TOC-DA