It just depends on your idea of healthy.

Good point. Perhaps this will clarify... Does casual sex contribute to one's overall sense of well-being, or is this 'wellness' only to be found in a monogamous, long-term relationship?

The important question here is: What do you think?
Consensual sex, no matter what kind, is healthy. Having an active sexual life contributes to well-being. I don't believe monogamy is natural (although I have been monogamous all my life). I really think it is more cultural than biological. But it is very important that the people you are having sex with know your intentions very clear so they don't get hurt in the process.

That is the issue that I run up against as I try to think this issue through. My greatest desire is that I don't cause 'hurt' to another person, yet it seems that sex is so tied up with feelings and emotions (at least from my perspective) that the potential for hurt is always quite high. I struggle with that...yet I really like to have sex...

If you want to find casual sex partners, there are many "dating" sites and apps that are well known as a source for finding "hook-ups".

There are many websites for that. If you don’t like the drama stay away from potential married partners, unless that’s their “thing”.

Yes there are. Try swingers' websites and hangouts.