Will this set my rear calipers to service mode Will it reset the level sensors on my headlights

Yes. The Ross-Tech VCDS HEX-V2 interface can perform rear electronic parking brake service mode/basic settings on supported Audi/VW models, and it can also perform headlight level control basic settings/calibration on vehicles equipped with a supported headlight leveling module.

Can i adjust the fuel Guage on my 2019 vw Passat with this ? I bought a new sender and it will not go all the way to the full mark now .

Yes, VCDS can access fuel level sender/instrument cluster adaptations on many VW models, but it usually will not “force” the gauge to read full if the sender, float arm position, tank side, wiring, or calibration is wrong. For a 2019 Passat, if the gauge no longer reaches full after sender replacement, first verify the sender is the correct part for the vehicle and that the float arm is not bent, restricted, or installed incorrectly. VCDS may help check measuring values/adaptations, but it should not be used to mask a mechanical sender or installation issue.

will this product work with a USB-C computer plug in site?

The interface cable uses a standard USB Type A plug, but would probably work with a USB Type A to USB Type C adapter.

Can this device work with Mac computers. Also will it work for my 2019 Audi Q7. Finally, will it reset the service interval (not just oil change warning)?

VCDS can potentially work on Mac, but is not technically natively supported. You can find more info here - https://www.ross-tech.com/vag-com/faq_1.php VCDS will work on the 2019 Audi Q7.

Can this be used when changing the trans fluid to monitor temperature when trying to get the fluid level correct ?

Yes, this is should be able to monitor trans temp through TCM if available.

Can this activate the fuel pump , or prime the system ?

Yes, the exact procedure may vary by model but it is capable of doing so.

Can this unit reprogram a replacement key FOB for a 2019 Jetta R?

No, typically these units have very limited functionality for key programming and cannot actually program new keys as this is a dealer restricted function.

Will this work with windows 11

"Release 25.3 works with Windows 7, 8, 10, and 11 (both 32-bit and 64-bit) Release 25.3 must be used with a licensed Ross-Tech interface." - Ross-Tech

Is the registration accessible from more than one computer? If I change computers but still use it for same vehicle, does that mean a second registration?

The Hex-V2 acts as a dongle, allowing you to use the software on multiple computers by simply installing the VCDS software and connecting the interface. The only limitation is 3 registered vins max.

Will this reprogram brake module and transmission control module on a 2007 Passat Wolfsburg Edition?

Yes, this should handle both functions fine.