Transparent GIFs

OK, so IM having a problem when exporting in gif format to complete it in Photoshop. There always seems to be this ugly jagged edge around the whole gifs in white about 1px. How can I fix this so it's very smooth as intended?

Also, why do some of my gifs turn into almost a poster-like style state? my gifs are meant to be "realistic". does that make sense? 

Thanks