Recommendations

Hey guys, i have some questions regarding the recommendations for the questbridge application. The questbridge application recommends that I also do a common app so under the common app would I also have to select all partner schools that i am applying to that are available? Each school also has their own recommendations required so is it ok to have the same teacher write the Questbridge recommendation and the recommendation for the common app? Would it be better to have different teachers write the recommendations for the questbridge and common app? I know that my school uses noviance for doing the recommendation stuff too but i dont know how that effects the recommendation process? Also im having a hard time deciding between teachers to write the questbridge recommendation. It says that it strongly prefers core subject teacher recommendations but i’ve known my engineering/CTE teacher for longer and i want to do Computer/Electrical Engineering in college so would it be justified to have him write one of the recommendations and have my Chemistry teacher write the recommendation through the common app? Or would it be best to have my math and science teachers do the questbridge recommendations and have my engineering teacher write his recommendation through the common app? Thanks so much in advance!