First I would like to define some categories/terms
Morally Impermissable or Morally Prohibited
Morally Permissible
Morally Praiseworthy
Morally Prohibited is that which we Ought not to do.
Morally Permissible is that which we are morally allowed to do (ie not Morally Prohibited)
Morally Praiseworthy is going above and beyond our moral obligation due to our moral prohibitions.
Next I would like to point out the Ought implies Can. Ie something can be neither required of you nor praiseworthy for you to do if it is not possible to do. (However you may only be required to try and fail to do something.) Likewise something cannot be Morally Prohibited if it is impossible not to do it.
Now to address the terms of Bloodshadow's interest.
Self Interest is the desire to pursue one's own interests.
Now if someone believes that altruism is right and thus is Morally Praiseworthy then their self interest is the pursuit and practice of altruism. So self interest cannot always be immoral.
Now selfishness. Selfishness has different definitions based upon the person defining it. My definition is
Selfishness is the degree to which one is concerned with promoting their own wellbeing instead of promoting the wellbeing of others.
Now with this definition if any amount of selfishness was immoral or Morally Prohibited then we all would be obligated regardless of the actions of others to give all of ourselves to others. (our time, our vital organs, our flesh as food and our leftovers like bones and skin as raw materials for shelters.)
I do not agree that we have the above obligations. (which is obvious due to I am still living) So some amount of selfishness is Morally Permissible.
Now Greed. Greed likewise has differing definitions. My definition is
Greed is concerning oneself with amassing wealth to a foolish degree instead of pursuing other matters typically by favoring one type of wealth massively over all others. (most common is coinage over relationships)
Wealth is the value people have for things, ideas, experiences, accomplishments, relationships...
Now concerning oneself with amassing wealth is not always a foolish pursuit. After all many would agree that families and friendships are good things. What makes it sometimes foolish is if one seeks a poor sampling of types of wealth. One who seeks coinage and money at the expense of good times with friends and family is often thought of a frugal and thrifty if not done in excess. But if it is done in excess (scrooge) then you can see why it is termed foolish.
But is foolishness cause for declaring something morally prohibited? I would not think that foolishness would be morally prohibited. So if Greed is morally prohibited it is prohibited for another reason not conveyed by my definition. Maybe your definition would be more enlightening.
Edited to add more.
As to my personal beliefs on morality.
I believe that we all have certain possible obligations to fulfill and certain praiseworthy actions made available to us. I know that some humans are interested primarily with searching for and following the obligations and fulfilling the praiseworthy opportunities. I also know that some humans have things that they find more interesting then seeking to know their obligations.
So from that believe I see many humans accidentally break obligations through ignorance or seize praiseworthy opportunities through ignorance. I see a few seek and seek and seek hopefully the process moves their actions closer towards accidentally obeying the obligations than toward breaking them.
So can humans be innately moral or immoral? Yes.
Are they? No because they do not all do the same things so the majority both accidentally break obligations and seize praiseworthy opportunities.
