I've never heard of or seen just the front shoes wear, so that is new to me. Its not normal. Both the e-brake and the hydraulic cylinder push on the front and rear pad equally (normally).

I would check the e-brake mechanisms (drum off) and make sure both shoes can move when pulled. Same for the hydraulic part.

Yes, you should flush your brake fluid every couple of years because the fluid absorbs moisture, which will eventually rust and pit the piston bores and they will then leak. It will save you money down the line. You don't have to use a power bleeder, but you can. I like the Motive Products power bleeder (there is a review here somewhere). Standard or gravity bleeding will work for a simple flush though.