Its quite tricky to be a rly good runner you have to know when and what to relax and hold joints
arms are usefull for keeping balance but u can choose not to move them (but just like mocu said they do have a weight)
Chest will certenly screw you'r run it would make u fall on side and you will have no choice but to do a jump or something like that
in my opinion if ur weight is too heavy and its not possible to regain you'r balance then I suggest you do a roll,its rly easy you just have to contract both of ur knees and make yourself look like a ball and then poof extend them but dont fully do that after you kick the ground
arms are important in rolling too, if you need more information on how to roll then just ask ;)
My Youtube channel : Mocucha Toribash
Ecchi, in an other idea, find and watch poop sparring (an evolution clan member), when he started sparring he was bad just because he wasn't usued to that, he was still trying to do tk, wushu or abd style moves, then he is now really good and fluid. Let time to the time, training, training, training ;)
My Youtube channel : Mocucha Toribash
I never tried to being cocky or something like that and make you feel as a shit. But yeah, i think if you want to become good at something you need a honest feedback on it ;)
I am glad to see you never gave up and still there.