To answer your second question, I am not sure it goes both ways. I think it may be more common for us to be accepting of theological opinions than for the Orthodox to be. The reason I say this is because I have heard Orthodox criticize the Catholic Church over "limbo" even though limbo has never been a doctrine, but has always been held as a theological opinion. Unfortunately, sometimes theological opinions are elevated and promoted in such a way that it comes off as if they are doctine (which is what I have heard has happened with limbo in the past) but they are still, nevertheless, theological opinions.
29, 1951, in his Allocution to Midwives, Pope Pius XII declared:
"In the present state there is no other way of communicating [sanctifying
grace] to the child who has not yet the use of reason [other than Baptism].
But, nevertheless, the state of grace at the moment of death is absolutely
necessary for salvation. Without it, it is not possible to attain
supernatural happiness, the beatific vision of God. An act of love can
suffice [i.e., Baptism of Desire] for an adult to obtain sanctifying grace
and supply for the absence of Baptism; for the unborn child or for the newly
born, this way is not open."