Car appreciation... the aesthetics, the engineering, etc

Tear in the sidewall unfort.

Gutted. I had that happen on a previous car, Toyo Proxes with less than 500 miles. Silver lining that straight swapping another new one was absolutely fine.

Better tyres as in quality or life left go at the back?

Life left. Newer tyres with more tread at the back.

https://www.uniroyal-tyres.com/car/tyre-guide/tyre-knowledge/good-tyres-on-front-or-rear

If you replace old tyres with new tyres and this does not apply to the whole set, there comes the question: Do you fit the new tyres at the front or back? Regardless of the drive type, we recommend not fitting the better tyres at the front, but always fitting them at the back. The reason is simple: The rear axle ensures the tracking stability of a vehicle.

https://kumhotyre.co.uk/kumho-news/should-you-fit-new-tyres-to-the-front-or-rear/

CONCLUSION
To give the best possibilities of a vehicle handling safely when fitting new tyres to a vehicle in pairs, it is advisable to fit the new tyres to the rear axle.