If you have solid (even reasonable) IO, then moving things in and out of working memory is not painful. We have some customers on non-EBS spindles that have very large working sets (as compared to memory) ... faulting 400-500 times per second, and hardly notice performance slow downs.
I think your suggestions are legit, but faulting performance has just as much to do with IO congestion. That applies to insert/update performance as well.