In short, and to the effect of what @Steven is saying, yes you can obtain and purge excess line styles from a model, but it is best that you first try to work something out yourself (for one, it will help you learn! But it is also suggested that you have an attempted graph of what you are trying to achieve in any post on this forum, see here if you haven’t read yet, but I have a feeling you must’ve since your first post was very good 
How to get help on the Dynamo forums)
Once you have tried something out, if you can’t figure it out on your own, as @Steven said, make a new thread, since this would be a different topic than the one we are on now. 
Also always make full utilization of the search ability on this forum when trying to find solutions. I am sure you will find a way to get rid of those pesky extra line types 