Need more info. I assumed you made "Everyman" an archetype to be added to the Ninja correct? You didn't start a whole new class from scratch?
When I look a at ninja I see Fast Stealth and other Rogue Talents without issue.
Going to assume you decided to make a whole new version of Ninja. In which case for the Custom Ability you need to allow your brand new class to "
Allow Custom Abilities" of Rogue. This is option is found on the "Class" tab of the editor. That will let you see Rogue Talents along with Ninja Tricks.
You could also overwrite the custom expression for the Custom Ability to use abCategory.? tags. In example the community "Expanded" archetype for the Unchained Barbarian allows all rage powers to be used. I had to modify the base classes custom expression to allow this. See
THIS example on GitHub from the community Repository.
Unless Everyman Ninja changes 99% of the class I would NOT re-create a new class. You will end up with more issues down the road with Pre-Req of feats, talents and tricks. This is because your new class is not going to be treated as a Ninja without allot of extra work. An archetype can be used more easily to add features or make changes. An archetype does NOT have to remove abilities. It could instead just add and then you won't have to deal with tricking HL into treating your new class as a the Ninja Base class.