"The stronger your faith in your own true god, the easier you will find it to be around the worshipers of false gods."

A little true but mainly false.

It is true that having strong faith lets you tolerate other faiths better in the abstract. 

However, actively exposing yourself to heresy, as Yarvin suggests here, becomes more and more intolerable. You notice they're ritually unclean and it's more and more like touching poop. 

Something something the best lies have a truth backbone. 

Fascists gonna fasc. It's not a big deal to me that Fascists exist. Even that Fascists are super common. However, if a Fascists starts fascing right in front of me, I violently GTFO. E.g. exploit certain aspergoid embarrassment immunities to simply excuse myself mid-sentence, then walk away. Gonna puke otherwise. Or, worse, reveal my power level in public (for the purposes of intellectual bullying).

"It is very limiting to require that everyone around you worship only true gods."

If you allege you're my friend, then I insist you never talk about politics. "This is politics too?" Yes. "Even this?" Uh huh. Likewise, I don't constantly proselytize Neon Hillism at you; the difference being I'm not a graceless Americoid so I do this without having to be asked. 

Religion and politics are already the canon impolite topics. Americoids still talk about them more often than non-politics. They especially favour State-worship, thus combining the two. Gross. 

"If you can’t be angry at the people around you, but you can’t help noticing their systematic errors, you have to find a way to pity them instead."

Did Yarvin just suggest you hang around folk you pity?

Especially bad advice for Anglos or Saxons, who habitually start to hate anyone who shows weakness, thus inspiring pity. This caused several extirpations in colonial times. They pitied the locals, thus hated them, thus killed them all to show that they could, proving they deserved the pity and thus the hate.

Especially since you can't release the psychic tension by killing them, absolutely avoid folk you pity.  

Notably Christians are significantly less ritually unclean and thus significantly less disgusting. Exception: Christians who come to my house and then start incompetently slagging my faith. Bruh. At least don't be a moron.