- status changed from closed to reopened
- resolutionfixed deleted
- milestone changed from 1.8.1 to 1.9
Most of the stack inconsistencies you're mentioning shouldn't exist IMO and are probably bugs, although a few are explicit like the one in .replaceWith that I haven't explored.
Thinking about it further today, I'm inclined to never stack .before or .after.
A complicating factor is that #12392 is impacting .before, .after, .replaceWith and .add in some cases. The patch I backed out tried to fix that problem but there were regressions in all the IEs.
The ability of jQuery.merge to modify its first arg is great, until you don't want it.