What is necessary for salvation is to avoid sin. To hold deathist views, or to vote for someone with such views is a grave sin of participating in murder.
The doctrines of the Church, whether consiliar or magisterial, or matter of natural law, are all binding. Further, matters of natural law, such as abhorrence of abortion and moral inacceptability of voting for the proaborts, is binding on everyone, not just on Catholics.
While the Church, acting on incomplete scientific knowledge, held an incorrect theory of late ensoulment, she always held abortion to be a moral evil, even if the late ensoulment hypothesis stood in the way of technically equating it with murder.
What is necessary for salvation, Alex, is God's mercy. Without it, even the saintliest among us is lost.
I agree with the rest of your reply. The Council of Trullo actually called abortion a murder. That seals the issue of abortion in the East. Unfortunately, the Catholic Church does not recognize that Council, so abortion cannot be considered equal to dogma.
The real problem, Alex, is in what the Church preaches and what she practices. When those who openly profess abortion are summarily excommunicated/anathematized then pro-abortionist Catholic politicians may think twice. You can't preach abortion as grave sin and allow public officials who support it to receive communion and remain in the Church.
If Pelosi and the gang can receive communion, why shouldn't Catholic voters vote for the pro-abortionist Obama? You can't have it both ways. You can't have a bunch of bishops cackling against abortion, yet allow communion in their diocese.
The Pope can always call a Council which would make the issue binding to all. But the Church choose to talk and do nothing. Talk is cheap, Alex.
Remember that Christ says in the Gospels that he came not to bring peace but a sword (to divide the sheep form the goats). Overturning money changers' tables was not politically correct. Christ did not follow the Church's luke-warm non-confrontational policy of appeasement with everyone and all.