Katie65,
Please consider that you do not have to regrind lines if you do not want to. It is an optional feature. If you want to maintain your favorite lines, hold onto them and maybe regrind a line you are less interested in. This feature is very much an extension for players Who have researched and obtained all ships before and are looking for a new goal to achieve.
The reason each PT the ships are reset is since each patch contains different features and content to be viewed on constantly changing ships. Customising the "grant" list for each patch would be a resource sink for development staff. What I would recommend however, if there is a series of ships you are enjoying testing on PT, set them as Primary Ships (right click on carousel, set as primary) that way they will be in the primary position within your ship line up.
I have not heard of the issue regarding coal on the PT, however, this definitely does not sound intentional. We are going to look into this situation and determine if something strange is occurring.
Regarding content such as Savage Battles, remember that content is optional to participate in it. If it appears within PT as part of a requirement to unlock other content, it is because we need feedback on it, if you do not want to play it, then don't.
Fem,