I'm a Ritchey Road Logic fanboy.
Here's mine.
Yours looks great and that's a pretty nice build as it sits. I have mine set up kind of mildly modern and in sort of sensible roadie mode versus my other builds which lean more gravel / ibob / rando bike.
-I love downtube shifters but for my roadiest bike I appreciate the sti's. Matter of preference though. I think your drivetrain looks pretty good and I'd ride it as is rather than spending money there. I have 6700 on it and it works great. I don't miss the 11 speed drivetrains I have on my other two bikes when riding the Ritchey.
-I think a 50/34 works out perfect for a roadie if you're doing some real climbs. I have a 46/30 on my other bike and appreciate it but I do spin out especially when unloaded and trying to go fast.
-The RL's have a lovely ride, the sort that people rave about with steel bikes. One upgrade that I found really made a noticeable improvement in ride quality and lets you feel that lovely steel feel is nice supple tires. My RL fits up to a 30 mm tire. Challenge Paris Roubaix which stretched out to 30mm are the best riding tires I've had on the bike. Currently sitting on Vittoria Corsa G 28 mm which are also excellent.
-Ritchey has some great compact drop options for bars. I find those way comfier than a deep drop. If they don't have a non oversize clamp option look at the Nitto options.