Yes.
If you could trace their ancestry back far enough you could probably find common ancestors for any pair of presidents, so in a way, they are no doubt all related. However, in the usual sense, people are said to be related only if the relationship is known and fairly close, so in this sense, US presidents are not all related. Some, of course, have been closely related to each other.
all gods are related in some way
Well, since jellyfish are all JELLYFISH that is a way they can be related, but otherwise, some are blue, and some are purple.
yup
Yes all the gods are related in some way they maybe distant cousins
Yes, they are, in some way, shape or form
Hades is related in some way to all other Greek Gods, and Goddesses.
yes they all are related in some way.
Yes, all pure-bloods are related in some way. Ginny's grandmother was Sirius' niece.
No- not in any known way Madison and Taylor, however, had the same great-grandfather and so were third cousins.
Related as in cousins or brothers, no. They are not related at all.
Yes, all pure-bloods are related in some way. Narcissa Malfoy, Draco's mother, was Narcissa Black before marriage.