Does anybody know if flipping, earth being without strong/stable magnetic field for decades/centuries could have been cause of dinosaur extinction?

According to Wikipedia [0], there have been 183 magnetic reversals the past 83 million years (and many more throughout the history of the Earth, including the reign of the dinosaurs). The weakening of the Earth's magnetic shielding is no laughing matter, but the impact of the Chicxulub asteroid was certainly far greater.

[0] https://en.wikipedia.org/wiki/Geomagnetic_reversal

I know almost nothing about this but I'd say this is unlikely. The dinosaur era spanned millions of years and the poles flip several times per million years. So they survived through dozens of flips.

There was a 2013 paper titled "Mass Extinction and the Structure of the Milky Way" that you might find interesting: https://arxiv.org/abs/1309.4838 - I don't know if there have been any significant follow ups since it published.

Basically our galaxy is a spiral galaxy with four arms, and it's rotating. The center moves slower than the outside, and our sun's orbit is near the inner rim of the Orion arm. We orbit the galaxy roughly every 240 million years and in that time we cross the dense galactic arms every so often (arms aren't symmetrical).

The paper: "A correlation was found between the times at which the Sun crosses the spiral arms and six known mass extinction events."

Yeah, and they only had to design an entirely novel and significantly asymmetrical model for the shape of the Milky Way Galaxy to do it.

You'd like to see that in your lifetime?

It's gonna be a bad time, man.