I'm one of those people who can ride the hell out of a bike but is utterly incompetent on anything more mechanically sophisticated than changing a tire or adjusting a seat, so bear with me if I ask some stupid questions. Please note--I do not want advice on my shifting/riding style, which I know is highly unusual and one that I've adopted through a lifetime of trial and error. I have short stocky legs, and this works really well for me.

I have a 2017 FX 3, and I spend well over 90% of my riding time on the large chain ring. I go up most hills on the large chain ring. It is 48T. My smallest gear in the rear is 11T. I actually use the 48X11 quite a bit running level, not just downhill. I feel like I actually could make use of a higher gear ratio.

Everything on the drive train except the pedals is the original stock equipment on the bike.

So my questions are: 1) Can I replace the 48T ring on my particular bike without having to change a whole lot of the rest of the drive train? What else, if anything, would I have to change?
2) How much of a difference would I feel between 50 x 11 and 48 x 11?