Thanks.
answer c) I want to create one model (series of types) and if I change dimensions on it, the dimensions in 2d drawing should automatically change.
There is no way to achieve your goal of having a dynamic, multi-input, single field in a BOM that requires no intervention when things change. I'm going to assume based on the context of this thread that "the dimensions in the 2D drawing should automatically change" really means "the Parameter type cell values in the BOM should update" and not "dimensions on the 2D drawing".
However, you can populate 3 columns with the 3 dimension values. Move the columns close together on the BOM, remove the vertical BOM lines, remove the headers, and it will
look like what you want. Insert custom columns of text and just populate them with "x" between the values.
Please see the example ZIP file with the parts, assembly, BOM template setup, and drawing example.