Another suggestion: Encapsule your equations with "`":
a² + b² = c² → a²+b²=c²
That way the reader can better differentiate between equation and text.

In case you don't plan to stay dependent on your website, here is how I manage those special characters:
I just put some of the useful symbols(like ∇(alt gr+shift+2) or ħ(alt gr+h) or some greek letters) on my keyboard.
And I don't know how far this is implemented on other OS's, but on Linux you can type super-/subscripts by typing ^ or ˇ once and then the symbol/number. Sadly this only works for numbers and ⁽⁾⁺⁻₍₎₊₋ . Trying to use it on letters yieds things like î and ǐ.