[Trainman1965]

Well the weight a loco will pull is all up to the loco. I have one RS3 that will pull all the cars i can put behind it and then i have one more that does good to pull 5-6 cars. just have to hook them up and see what it can do. no for the 90 deg turns you are going to have to work them out. If you are making a turn in a corner then start making the trun before you get to the corner. sweep it out and add a brace from the corner out to the track.