Sorry in advance if I'm covering something already covered.
Actually, a lot of people do something similar, though not with just ONE person they've never met before. I don't know how your travel time share works, but a lot of folks who want to travel go with tour groups and such. Of course, it's not a fool-proof way of coming back safe, but if you stick to very touristy places, you're generally safer. Especially in countries that rely highly on their tourism. They don't look kindly on criminals taking out the people that are helping the economy. You're probably more likely to be scammed or stolen from in those places, but not harmed.
Look up crime-rates and such. I know Canada has an official website that tells citizens where it's safe to go, not safe to go, and HOW safe it is to go. Not sure if other countries have something similar, though some of the information could be used for people in general.
https://travel.gc.ca/travelling/advisories
At any rate, I really envy you! There are so many places I'd love to travel, but due to finances, family, and health, I doubt I'll be able to. So I hope you find someone to go with, or a tour group, or a relatively safe location and just GO ENJOY!