My general philosophy is that sometimes you are delt some cards and you play them like they are. This is your bike. I agree that it's possible the bike could be too small. But this is your bike, and it's pretty cool.

I'd venture to guess that your riding style fits this bike pretty well and tha you've made decisions to the best of your knowledge keeping in mind your riding style.

When the geometry of a frame is smaller than optimal you typically see folks use longer stems. I would also recommend a 100 (maybe even a 110).

I have studied fit systems for a long time and I really enjoy it. Not trying to toot my own horn here. I just want to convey an opinion that may help you find something optimal. I have tons of resources too. Let me know if you need more information.

Best,
Mary

P.S. The picture makes it look like the nose of the saddle is tilted up just a hair. If it is, your arms could be working harder to keep you from sliding back with out you even realizing it. Eliminating strain and force with fit sounds like exactly what you are trying to do.