I’m sorry to hear about the pest problems you had ! Botrytis can be a difficult thing to deal with. Is it in the old stems, is it lurking in the soil ? Has it made it’s way down to the crowns ? Aside from good hygiene, I suspect that a person has to spray. And spray preventively, before any symptoms show up. Not something anyone looks forward to.
The issue with bad bud covers is an interesting one. And I’ve heard that for some registered varieties, it becomes more of an issue the older the plants become. It may have to do with early season temperatures, but it may have to do with other factors as well. We selected a number of seedlings several years ago, from plants in seedling blocks that appeared to be mature. We dug them and planted them again from the resulting divisions, and two years later when it was time to do further selection, we were wondering why in the world we had ever kept them, because of the poor bud covers they had. This seemed to have to do with the plants being older, because they had looked fine when we first selected them. One would think it would be more of an issue with flowers that are double, but less-double flowers can have short bud covers too.
Established varieties like Old Faithful can have poor looking bud covers as well, but somehow they develop just fine, so I’m not sure that poorly covered buds is always the kiss of death, but it’s something one would rather not see, that’s for sure.