Loss of work due to bugs

It's always a pain to hit things that bite like that. Your autosave situation is certainly a mess! And I do see that some users have constant issues with Ae comps, which again, would be maddening. Total sympathies on that. 

There are others here that actually might help you get those sorted better, as for many shops, they don't have near the crashes you're getting. It would be nice to get you past that!

I can answer about Warp and remapping ... Warp is a two-part process, first running the clip to analyze, then from the analyzed data completely re-creating the clip's pixels. It is the most intensive computing process in Premiere, even more demanding of resources than Neat Video Noise reducer. 

Time remapping also requires completely re-computing the pixels displayed per frame ... and is also a heavy resource hog.

Applying them simultaneously can easily cause processing errors. Which is why one is not supposed to do so.

Using Nest, you can apply one, nest the clip, then apply the other, and that normally works.

But realistically, given the massive demands of both operations and the limits of any computer's capabilities for doing multiple complex operations that both affect all pixels of a clip even sequentially, it is more practical to do one, do a render & replace to proper DI standards, then you have a 'clean' clip to apply the other to.

You can always 'restore unrendered' if you need, but other than that, playback and further application of effects and exports will be much smoother and faster.