The idea of playing music from the past is an relatively new (in the last century and half) phenomenon. Before that, pieces would only be played at best for a few months before the performers and audiences moved onto the next thing. Now, with the backwards looking aspect of Classical Music, we have a declining and aging audience base that was further exacerbated by the focus in the past to pitch itself as an elite art form instead of reembracing its roots as a living art form.

There have been many ways to try and address this, ranging from the sex sells approaches to various better attempts. To be honest, I don't know what will succeed whilst keeping integrity intact. The largest problem these days is that audiences don't know the difference between a lemon and a jewel, as the appreciation of music now (not just classical music) has become a matter of marketing and looks rather than substance...

As for your last question, I tend to (hopefully) occupy the more inventive end of given free reign! I find that a focus on avoiding mistakes is a sure fire way to get overwhelmed with doubt and stage fright! You can't please the whole audience, so it is best to play in a way that pleases and engages yourself!