At first i thought Sha'Carri would be just a "one time LI" MC would have the chance to smack on the trip, but as nothing really happens there between them and the brief appearance she makes on Nikki's path, i think theres a chance of her maybe transferring into MC's school, or they can bump into each other and exchange numbers, my guess here would be on Val's path first and then in some different occasion on other paths.
Melissa is already having wet dreams about MC, so i think its a matter of time until they end up having something with each other, but if MC is on Erynn's path it will not happen as she would not cock block her daughter imo...but this path will create a lot of drama, with both Erynn and MC's mother as they would be against it imo.