If you just want to post something for others, try http://www.4shared.com/ and set up a free account.

How an arranger handles chord changes is totally down to the arranger software, (Different types of voices require different settings, and while Factory styles are all done for you, if you use a converted style or convert from Midi, you will need to set them manually) so providing the VSTi is setup to receive and act on these changes, (Some sounds are just for solo sounds, like the Yamaha SA voices are) then there is normally no problem.

Like most things it will initially be trial and error until you get the hang of it.
Hope this helps

Bill