There aren't that many choices in the remaining routes. In Kazuko route has 2 choices that will change the CG after it to with or without glasses, in Momoyo just don't be a dick and you should be fine, Chris and Miyako has no choices at all and the agave after split is when you have to choose between supporting the Itagaki family (Tatsuko route) or refuse Lu-sensei to help them (future with the Kazama family). I think hermit crabs has one choice where one leads to Yumiko end, the other to hermit crabs+. It's very hard to fail the routes in Majikoi S, maybe only during child route you need to watch out and help Koyuki for her route, the other route are impossible to fail.