The errors you are getting with the = sign are bogus-- the real culprit is the &. Change it into a character entity and you're good-- the = errors will vanish.
& amp ; without spaces. Yes, you'll have to do this manually, unless you have a back-end script to regex through links and replace them for you. Browsers and other user agents already know to automatically retranslate those back to &'s again.
Any other errors with characters from the validator mean, not to comment them out with slashes but to use character entities (because it cannot tell when you want to use a reserved character like > in your cdata/content, and when you mean to use it for its special meaning like <a tag>).