Tello gives you a real (US though) number, E911 and all, for 5 USD a month. You get an eSIM you can activate from anywhere in the world via Wi-Fi Calling. Send and receive unlimited texts and get 100 minutes a month for the odd service that insists on verification calls rather than texts. I’ve had zero issues.

Like basically all cloud providers, Oracle publish their public-facing IP address ranges.

https://docs.oracle.com/en-us/iaas/Content/General/Concepts/addressranges.htm

Many services block these because, as you are pointing out, standing up VPN tunnel routing on a cloud instance is sort of trivial. Cloud providers publish these ranges specifically so anyone can block them easily. If lemmy.world is not blocking Oracle Cloud already, it’s only because they just haven’t come around to it.

Mullvad has a 30-day money back guarantee.

Apart from that, some payment methods (like crypto) allow transmitting arbitrary amounts. At least, paying for years in advance works without issue. You could pay a few cents and try it out, but be mindful of fees.

Almost all extensions will weaken your security posture. In fact off the top of my head there are basically only two kinds of extensions that could improve it:

• ad blockers
• (maybe!) password manager integrations

Anything else is questionable at best. Maybe you could create browser profiles where you install extensions somewhat more liberally, with decreased expectation of safety.