It's really annoying that TeX is rendered outside of questions. On MO, we realized this and turned it off for the question list and main page. Since the SE overlords have more control, perhaps they could add a checkbox in the user options to turn this on or off, but I personally find it incredibly annoying that I get so much lag every time I go back to the front page.
The bug tag doesn't seem fair. This is a feature that some like and some (not just you, to be sure) dislike.
Your idea of having it be togglable seems like an ideal solution.
(Arguments based on the age of your laptop are probably not going to be very convincing.)
I think that often it is useful to have LaTeX in question titles. I am happy to lose a little time in the rendering of the first page and save more by avoiding to read a question I'm not interested in. I think that without LaTeX many users will turn to more generic titles, so that one has to open the question to figure out.
For instance one may want to give a title like "How to compute $\pi_4(S^3)$", but since LaTeX is not available, change that to "Homotopy group of spheres".