Hi,
Bootstrap has been extended and customized for Joomla since it lacked accessibility and didn't work well with language strings, and other Joomla-specific issues. I implemented some of these changes, others were forced by the bugsquad and I didn't necessarily agree...
The JavaScript select boxes aren't Bootstrap though, they're Chosen JS. You don't have to load them in your own component views if you don't want them.
For the Chosen long language string not wrapping, that's an issue where a Bootstrap btn-group has a nowrap, but we added specific CSS to fix this, not sure why it's not working. This is the CSS:
.btn-group .chzn-results {
white-space: normal;
}
The radio toggles are a huge usability improvement, but again you don't have to use them in your own component, they only activate when the form xml has class="btn-group" for the radio element