Hi Thailoneus,
Win 7 Home Premium 64 bit does not have a XP emulation mode. However this free program
http://www.howtogeek.com/?post_type=post&p=11060supposedly adds XP mode . I say supposedly, as I have no experience with it, others whom use it may chirp in. I suggest this as it may help you with your “Miles Black's Piano Master Class series,Jazz sax, Rock Sax, Latin” issues as well as any other XP programs you may have and still want to use. On a side note I’m still using an old Win 95 photo-editing program on Win 7 Pro.
Another option for your sounds are soundfonts. Click here for a list of free soundfont players
http://hiphopmakers.com/over-2000-free-soundfonts-free-soundfont-player and a list of free soundfonts. Here
http://www.synthfont.com/links_to_soundfonts.html is another list of free soundfonts with one being a GM set that you can automatically use with BiaB. Note that soundfonts may not be quite as good sounding as TTS-1 but they are good and the price is right.
Like Noel said lets get your sound source working first then attack you timing problem.
I hpoe this helps and good luck.