For option number 2, I don't think no-CB wars are needed in order to reach centers of reformation. There are three other ways to get there:
- As already mentioned, being the emperor and demanding unlawful territory
- No matter whether you are the emperor or not, you can try snake-claiming your way through the HRE (this can be done with the Age of Discovery ability that allows claims bordering claims - in my opinion that's the strongest ability for ordinary HRE members, even better than the AE reduction)
- In order to convert small princes that have a center of reformation in their capital, it is sometimes possible to use the 'Humiliate Rival' CB on them (unlikely because they are probably too small for you) or on their allies (that works better)
However, if you are not the emperor, then you also have to make sure that any center of reformation you do have to conquer for yourself will be in coring range. Vassalisations of random HRE members are the way to go because you can core territory adjacent to your vassals on the same continent.
- As already mentioned, being the emperor and demanding unlawful territory
- No matter whether you are the emperor or not, you can try snake-claiming your way through the HRE (this can be done with the Age of Discovery ability that allows claims bordering claims - in my opinion that's the strongest ability for ordinary HRE members, even better than the AE reduction)
- In order to convert small princes that have a center of reformation in their capital, it is sometimes possible to use the 'Humiliate Rival' CB on them (unlikely because they are probably too small for you) or on their allies (that works better)
However, if you are not the emperor, then you also have to make sure that any center of reformation you do have to conquer for yourself will be in coring range. Vassalisations of random HRE members are the way to go because you can core territory adjacent to your vassals on the same continent.