Installing TUSB3410 driver files on customer PCs

We currently have a product that uses the TUSB3410 to provide USB connectivity. We have modified the INF file to have our VID, PID, and description. This works, at least on XP, but it requires more user interaction that we would like.

When installing our software we copy the driver files to C:\Program Files\(OurFolder)\Drivers. When the user connects the device, they have to browse to (OurFolder)\Drivers and the correct sub-folder underneath that. This causes no end of confusion.

The first thing I did is to get the latest driver, 6.7.2 (we had been using 6.5.9017).
This file contains an exe, when when run installs a bunch of files to
C:\Program Files (x86)/Texas Instruments Inc/TI_WDF_USBUART_SINGLE_DRIVER_V6.7.2_WHQL/
Inside that folder is another setup.exe file, which when run copies files to C:\Windows\tiinst. Neither of these places is searched by windows when looking for a driver.

1) Am I supposed to run one or both of those exe files on the customer machine? Or should my installer copy some or all of the extracted files to the customer machine? If so, which files and where should they be placed? (I realize that I have to replace the INF file with my edited version that has the correct VID and PID numbers.) What can I do so that windows will automatically find the appropriate driver files when the device is plugged in.

Why are these files distributed as installers rather than a zipped folder? Does either one of the installers do something else that I must do in my own installer? Or that requires me to run your installer on the customer machine?

2) Will this driver work for Win 8 and 8.1? There is a November forum post that points to a 6.7.1 driver specifically made for Win8 -- is that post obsolete?

3) The current drivers won't install on some Win7 machines -- windows doesn't want to install the unsigned driver. From browsing the net, it appears that this is related to either Secure boot or Win7-64 or both. How can we get the drivers installed on these machines?

Thanks for your help,