How would you describe this rubber strip? Like how do I say it's not smooth and it's got all those little teeth cut into it?

It’s not corrugated. Corrugated means folded into a wave-like shape. I would call it ridged

Corrugated

I would say it's grooved or notched (or has grooves/has notches)

corrugated

It's form is like a 'rack' from a rack & pinion gear mechanism - but I wouldn't use the phrased 'racked' in this context. Possibly, 'striated', too.

Ribbed for her pleasure

I would call it a 'aesthetically aggressive rubber edge banding'. I would describe it as jagged/corrugated/ridged and malleable.

Serrated.

I’d suggest “ridged.”

Fluted maybe. But ridged is a safer alternative.

Corrugated or ridged

Ridged or perhaps serrated.

I would say it's knurled like the edge of a coin.

I'd probably call the shape ridged. In this context (on a flying V guitar), it'd be a leg grip.

Ridged, corrugated or toothed, depending on its purpose.

I'd say that is a rifle line, but I'm not native speaker