thepetersinger

Donate to highly effective charities (you can find my choice here: http://www.thelifeyoucansave.org/Where-to-Donate) and go vegan (or as near to it as you can manage).

It's better to give now, UNLESS you are a really smart investor (eg, the next Warren Buffett). Because there is a return on investment in poverty reduction too -- if families live better, their children will be healthier, will get a better education, and will get better jobs, and stimulate the economies of developing countries, thus reducing poverty and suffering in those countries, and it is better that this should happen sooner rather than later.

My view is that we ought to give equal consideration to the interests of any being that has interests. By interests I mean that the life of the being can go better or worse for that being - there must be subjective experiences, or consciousness. So the principle is really about giving equal weight to the similar conscious interests of all being.
The issue about beings without a central nervous system is whether they can have conscious experiences. Maybe some can, but I'm doubtful that bivalves like oysters and mussels can. If I'm right about that, it is OK to eat them. If you think it is doubtful, give them the benefit of the doubt.

It would still be a waste of grains and soybeans to feed them, and would still contribute more to climate change than eating a plant-based diet.

I don't think that there is clear evidence that GMOs are hurting bees and butterflies.. one early study on this caused alarm, but was later shown not to be valid. Yes, there may be some unknowns, but where a GMO crop has promise of substantial benefits, eg golden rice, or a drought-resistant wheat, it will be worth taking some risk, if we can minimize the risk.