Two points:
1) I'm doubtful that the distinction between lifesaving procedures and immortality will end up being a clear distinction. I'm optimistic that humanity will eventually have the capability to do things like replace lost limbs with new limbs. Once we have that level of capacity, most of the modern causes of death go away - if you survive to reach the hospital, you're likely to be able to leave basically good as new.
2) Given our current levels of technology, Western-level standards of living for everyone are not sustainable. Nor do there appear to be imminent technological advances that would make that sustainable. But radical life-extension technology (of whatever form) is also nowhere near imminent. Why do you think that the kind of technology advances you dislike are closer to achievement than carrying-capacity advances?
Some of your comments suggest that you would oppose carrying capacity increases (like colonizing other planets) even if they were within humanities capacity because these technological capacities would be bad for humanity. Assuming you are correct that these technological revolutions would fundamentally change human society, why are these hypothetical changes worse than the changes caused by developments like selective breeding of livestock, practical steam engines, cell phones, the Internet, or agriculture itself?
I'm not sure that regrowing limbs is much like rejuvenation. Most people die of aging, not accidents.
If you don't believe in an afterlife, then it seems you currently have two choices: cryonics or permanent death. Now, I don't believe that cryonics is pseudoscience, but it's still pretty poor odds (Robin Hanson uses an estimate of 5% here). Unfortunately, the alternative offers a chance of zero. I see five main concerns with current cryonic technology:
So I wonder if we can do better.
I recall reading of juvenile forms of amphibians in desert environments that could survive for decades of drought in a dormant form, reviving when water returned. One specimen had sat on a shelf in a research office for over a century (in Arizona, if I recall correctly) and was successfully revived. Note: no particular efforts were made to maintain this specimen: the dry local climate was sufficient. It was suggested at the time that this could make an alternative method of preserving organs. Now the advantages of this approach (which I refer to flippantly as "dryonics") is:
There is one big disadvantage of this approach, of course: no one knows how to do it (it's not entirely clear how the juvenile amphibians do it) or even if it would be possible in larger, more complex organisms. And, so far as I know, no one is working on it. But it would seem to offer a much better prospect than our current options, so I would suggest it worth investigating.
I am not a biologist, and I'm not sure where one would start developing such a technology. I frankly admit that I am sharing this in the hope that someone who does have an idea will run with it. If anyone knows of any work on these lines, or has an idea how to proceed, please send a comment or email. Or even if you have another alternative. Because right now, I don't consider our prospects good.
[Note: I am going on memory in this post; I really wish I could provide references, but there does not seem much activity along these lines that I can find. I'm not even sure what to call it: mummification? Probably too scary. Dehydration? Anyway feel free to add suggestions or link references.]