Let's go back to the relevant part of your definition:
Morality is the complex interplay between the needs of the individual and the needs of the group, with the group's long-term needs taking precedence over the individual's short term needs.
This says that individual rights exist only so long as the needs of the individual are congruent with those of the group. This is not always the case, and by this definition it may be morally permissible to sacrifice one or many members of the group in support of the long-term group interests. IOW, individuals have no "unalienable rights." The "lifeboat problem" suggests that the needs of the starving many can be served by killing and eating the tastiest-looking one.
Groups are made of individuals and the group must recognize the needs, indeed the "rights" of the individuals within it or it ceases to function (cf., the Soviet Union).
This does not offer any way for us to call the USSR "wrong" other than that it didn't succeed. At any rate, individual rights do not follow from the group's "recognition of needs and rights" does , except perhaps in a conditional sense. For example, the ruling groups of ancient Rome, Egypt, and even the U.S. South survived very nicely, even though they relied for their success on the conquest and/or enslavement of others. (The jury is still out on China.)
No. This definition states that an individual's short-term needs take a back seat to the group's long-term needs. Rights are not necessarily defined as a short-term need. Hell, rights are usually defined as that which, when exercised by an individual, invokes no obligation on the part of anyone else. In other words, individual rights should never conflict with the survival of the group (and most probably should contribute to that survival). That is why there is no "right" to housing, or medical care, or even food. One does have a right to voice one's opinions, but that doesn't mean others have to listen.
Needs, on the other hand, are things like food, shelter, sex -- that whole hierarchy thing I remember from psychology class. Sometimes the individual's needs will conflict with the group's survival (sex, for instance -- the individual sees this as a need, but rape and adultery place strains upon the group and because of this need to be discouraged).
What other objective yardstick is there? Long-lived groups (the Catholic Church for example) must be doing something right, while short-lived groups (Nazi Germany for example) must be doing something wrong.