I have called my locations A, B and C you refer to Blue, so I am not sure which one you have an issue with. Order Multiple means you have to order in a factor of this, so in this example you can only order 50, 100, 150, 200 etc. However this is only true when using SKU’s, with mixed locations if the components at location is set it will ignore this setting for all other locations, the argument being you should be using SKU’s.
It is difficult to answer your questions as I do not understand them. As for anything else you started by saying you could get nothing to work, I have now managed to get requirements into the worksheet for you, I cannot comment on every scenario and setting as you have not told me them. Please remember where we started this thread!