I had a Visual 1 controller until 3 years ago. Rock solid. As I remember it, all of the RS232 adaptors I have used had built in driver support in Windows 7, 8 and 10. The issue is usually not the driver for windows ... the issue is getting the LK software running. I never had any problems with that.
That is correct.
Keep in mind that if you upgrade the controller then you will need to reprogram it. While the programming paradigm is the same (and looks very much the same), you cannot transfer the program from a Visual 1 controller to a Visual 2 or 3 controller.
Should you decide to upgrade your controller you will get:
Visual 2
Internet access
Wireless IHC (pushbuttons, outlets, etc.)
Visual 3
Everything from Visual 2
Ability to use the latest dimmers (which are the absolute best for LEDs)
More CPU power in controller
Controller is supported by manufacturer