i would really rather we first see these words used without possessive endings, and then figuring those.
Agreed. It would make much more sense to introduce these words first without overcomplicating it with the possessive.
Nagybácsi, bácsi, bácsika, nagybácsika, ...
Nagynéni, néni, nénike, nagynénike, ...
These are endearing variations, so, everyone can have their personal preferences as to which ones they use in the family, etc.
Nagynéni and néni are the same?
In German Tante, aunt, néni is the sister of one of your parents. And Großtante, grand/greataunt, (nagynéni#) would be the sister of one of your grandparents. #But it seems we need a higher level in Hungarian "nagy nagynéni"?
Rather unnecesary complication to use the -ke/-ka forms when it is complicated enough.