There is nothing wrong with splitting an infinitive. Shakespeare does it and Star Trek does it.
Passive voice is fine. Sure it can be used to make the text impersonal and hide responsibility. But is can also be used to make the text clearer and to emphasize what is important. Use it as appropriate.
I don't think his point is that the you shouldn't follow these rules though. Surely nobody would think you shouldn't proofread? He is just stating the rules ironically with an embedded example. Most of his rules are fine.
What I take from it is that those points aren't important at all.
That's surely hyperbolic, because nobody would think about completely ignoring them. But they certainly do not make any text great, and they shouldn't be followed on the cost of something more important.
Use as appropriate, yes. But there are some writers who massively over-use it.
Most such rules can sometimes be broken to good effect, but they offer a useful default. In many cases, rewriting so as to "follow the rules" will aid clarity. Deviations and exceptions should be the result of careful consideration, not just carelessness.
There is nothing wrong with splitting an infinitive. Shakespeare does it and Star Trek does it.
Passive voice is fine. Sure it can be used to make the text impersonal and hide responsibility. But is can also be used to make the text clearer and to emphasize what is important. Use it as appropriate.