1. What length should I get I am 15 years old 174cm(5'8") 60kg(132lbs). I am Intermediate-advanced skier.
2. Shouldn't Nordica Soul Rider 87 be better at carving than the framewall, Caddy? It has a narrower turn radius at 15m and the framewall/caddy 17.8m.
171cm should be a good length/flex for you in a ski like the Framewall.
Turning radius is just telling you the approximate shape of the turn the ski will naturally like to do when on edge. Lower radius skis like doing shorter turns but are less stable at speed as they want to keep turning rather than going straight. Longer radius skis are more comfortable going straight but can turn shorter than their stated radius when properly flexed.
Flex, tip/tail shape etc will also effect the carving capability. Stiffer skis like the Framewall with little tip/tail taper will allow more bite when tipped on edge and a very powerful carve.