It looks like the offer is still valid. I’m going to guess it will count as interest income for tax purposes. Tastyworks is a brokerage firm. Your money should be as safe as with any brokerage.

https://support.tastyworks.com/support/solutions/articles/43000654011-open-now-2022-promo-faq#:~:text=New customers that open and,applying for an eligible account.