Hello Leo,
Congrats on your new Riv. It's going to be a good companion on your cycling adventures. You may be lucky and it will feel like a perfect fit right off the bat, and size wise it most likely will be, but plan on spending some time (and maybe a few hundred dollars more) on fiddling with the bars and stem and seat position to get things dialed in. On my Clem I went through two stems and three handlebars; on the Charlie Gallop, two bars and two seat posts. Both feel like old shoes now.
Concerning frame protection it's' probably not a bad idea but may not be absolutely necessary. On my 20+ year old Romulus I never put any protector on the chain stay and looking at the accumulation of black grease on it I kinda wish I had. But then when I stripped the bike down (to move all the parts over to the Charlie) I hit that grease with some olive oil and underneath was a perfectly good finish. That grease may have acted as a protectant on its own. You may wrap 95% of the bike with protective tape and you can be sure that it's going to be the 5% you didn't wrap that's going to get the ding. "Beausage" is a thing with these bikes and somewhat inevitable. Far be it from me, however, to discourage any efforts at keeping your frame fresh; I just am relatively lazy in this regard, and my frames tend to reflect that.
Anyway, congrats again and let us know how the relationship progresses!