Originally Posted by Quath
1) Kids should not be taken just because someone lives with multiple lovers.
2) Ability to visit partners in a hospital.
3) Insurance benefits apply to loved ones.
4) Tax benefits.
Beyond that, make polyamory not a reason that a person can be fired from a job.
I agree with everything with the exclusion of health care rights. This is just me thinking on a realistic level. As it is, fewer and fewer companies (in the US) offer health insurance benefits. If I were an employer and was asked to provide insurance to not only my worker and his/her spouse and child(ren), but also to two or three or more other spouses who do not work for my company, I'd scoff at the notion. I just don't think it's fair. Gay marriage is different in that it is still a one-on-one commitment asking for the same rights as a male-female union. It's just an extension of legal rights to the gay community through legal bonds. Polygamy rights as far as health coverage take it to a whole new, and I think unfair for employers, level.
The rest you discussed is more personal and family right oriented, for example hospital visits. I can make more sense of that in my own head. They are more family oriented and personal rights and freedoms oriented. No one has to pay out for these rights to be granted, so there isn't a reason to oppose them IMO.