There are some people who won't be convinced no matter what but on the other hand there are people who might be conviced to vaccinate against COVID-19 who are currently not planning to be vaccinated. What are the best online resources to point non-rationalists towards to convince them that getting vaccinated is a good idea?
I suggest the RaDVaC article, as evidence of what experts think about vaccine safety when they're focused on protecting themselves.
You might follow that up with this suggestion about why the FDA might mislead us: if people notice that some vaccines are safer than the alternative by really big margins, they'll start asking why we don't just bypass FDA review in some cases. That will bias the FDA to suggest that most vaccines are tough choices, which need the FDA's expertise to evaluate. But given big variations in how harmful diseases are, this will lead the FDA to be too cautious about the worst diseases.
Also, it can't hurt to mention evidence of asymmetric blame that motivates the FDA to overstate the risks of all medical treatments.
This depends a lot on the individual in question. My bubble is such that of the few thousand people I (indirectly, but individually) have any knowledge about their vaccination attitude, there is precisely one (the father of a friend) who has stated his intent not to get the shot. And I suspect he'll change his mind at some point in the next 6 weeks.
"non-rationalist" isn't a precise enough descriptor to have any idea how to convince them, and you haven't specified what level of effort you're planning to put in to convincing any specific holdout or small, identifiable group.
Personally, I don't care what people say on surveys. I care what they actually do, to the extent that it affects those of us who are vaccinated. When there are no queues nor limits on vaccines (that is, when the bottleneck is willingness, not availability, worldwide), if there are enough non-vaccinated that it noticeably impacts transmission rates and effects the vaccinated, then I'll figure out how to encourage more of the idiots to get it. My favored mechanism is vaccination patrols armed with dart guns.
But there's quite a way to go before everyone who's willing to get a shot worldwide has one. Until then, I'm fine with self-deprioritization.