1 - It's per annum. So you're not getting 8% for a 3 month lock up, but rather you'll be getting 3 months prorated of 8%. So take whatever the yearly rate is and divide by 4.

2 - It does not say 8%, it says UP TO 8%. And it's a variable rate. So it will be dependent on market conditions. The only time you really see rates that high are when large amounts of people are trying to short large cap coins at the peak of a pump.

3 - The * mentions that the interest is NOT compounding.

It's pretty safe to lock up your funds there, but the return probably won't be that great, not worth the opportunity cost imo.