The Heart aspect is more about Soul than actual hearts or love or stuff like that. 

Here, Here, and Here

They were never explained, just mentioned

There’re a alien

It’s not been explained in canon but through speculation the Maid class could be one that “provides itself with its aspect” or  “someone who protects themselves and/or others with [aspect],”

Not my thing but whatever floats your boat kid

In [S] Ministrife, a Cronus and Eridan agree to go on a date

Nope, the blood color is related to their moral alignment. Lime for Benevolent and Red for Malicious.  If the Father lays the egg then the offspring’s alignment will match the parent of the same gender and if the Mother lays the egg the offspring’s alignment will be the opposite.

Yo

A Page of Breath is a natural leader. A Page creates or provides others with their aspect (the latter in this instance) and Breath can be inferred as meaning Direction. So a Page of Breath provides people with Direction. Allowing him to lead an army to a specific goal very easily. Pages also take a long time to actually embrace their role and this Tavros (or (Tavros) as he’ll probably be refereed) has had a lot of character development and time to work towards his role.