Is there anything for which one would be willing to permanently give up all sex, masturbation and orgasm?
ETA: ok, that OP title is supposed to say “permanently give UP sex”; not permanently give sex. &aha.
Knowing that I will be gainfully employed from now up until the day I die.
Good answer. 
Such a deal with the Devil would result in you dying tomorrow.
Sex is overrated. I like it fine, but intimacy and friendship trump sex any day for me.
And?
really fantastic sexy dancing with multiple very good partners 3 nights a week.
This is probably a true deal with the devil as likely nothing would make me want sex more.
Nothing. Sex is one of life’s few sublime pleasures. This is like asking for what I would give up laughter or friendship. These are things that make me happy, and a life without them would just be sad.
Nothing.
About 11 years ago when I had my back injury, I couldn’t for about two months. Extremely frustrating. I can’t imagine that as a permanent condition.
Are we to presume that we’re still capable of having children (possibly with medical aid)? Because that’s something I haven’t done yet, but would very much like to eventually.
And could we still take part in sex acts (such as oral or manual stimulation of a partner) that don’t lead to us having orgasms?
Yes and yes.
Under these conditions, I would take the deal for lifelong health, success in my acting career, etc.
I would trade in sex for something better than sex. I don’t know what that could be. I eagerly await the invention of the Orgasmatron.
I would trade sex for being able to use heroin without any addiction or health consequences.
Ahh but what if you were a heroin addict who wanted to get clean; would you trade sex for sobriety?
I have never used or been addicted to heroin, but I have been addicted to Xanax (which some say is harder to kick than heroin), and I was able to detox from that as an outpatient, and I didn’t have to give up sex.
So, no.
Try to answer it as a hypothetical; as if giving up sex (forever) is a prerequisite for you getting clean. Would your answer change?
No, getting clean is not worth giving up sex. I would require something better than mere sobriety.
Do I really need two kidneys? 
To answer the actual OP question, I can’t think of anything.
Not a thing.