As far as I understand it, there aren’t any meaningful performance issues caused by child themes. What’s the reason you would want to do this?
Two reasons.
First, my child theme – currently on my site at http://billbennett.co.nz is massively minimal. I don’t think I’m seeing the performance benefits of this because the parent twentyeleven theme includes tons of php and css that doesn’t get used. I checked this by benchmarking speeds of the current theme versus a basic, old-school WordPress theme.
Second, I want to package it up for redistribution. Sure, I know I can do this with a child theme, especially when the parent is the standard theme, but it would be cleaner as a standalone.
esmi is right on. It would be very dangerous to try to strip out any parts of Twenty Eleven, particularly for redistribution. Twenty Eleven can handle a lot of use-cases, and I don’t think you’d want make the theme less flexible.
With that said, if you really do want to change things, I would rebuild the theme on something lighter weight.
I like the HTML5 Reset WordPress theme and you might particularly be interested in starkers.
Like I said earlier, if you want to package for redistribution, you’ll need to consider other ways the theme might be used. Make sure to use the Theme Unit Test.
