I'm not entirely sure parenthood is something I want to tackle. I have good genes to pass on and think I would make a good parent and produce a good offspring, but that would entail a lot of sacrifice. It's the ultimate commitment. I can barely handle the prospect of a romantic relationship just for the sake of how much it forces you into the external world, forces you to constantly compromise, takes away so much of your freedom, virtually removes any bit of private alone time, etc. A child would be that tenfold, only without the option of ever being able to walk away.
Although, I am very good with kids. I just can't handle them for too long, let alone 24/7 for a minimum of 18 years.
As for what a child would think of their INTP parent, probably that they're very open-minded/accepting, calm, and fair, but also maybe not very understanding or sympathetic of their problems. I think an INTP parent would likely see normal adolescent issues as extremely silly and for the most part dismiss them. They might help them with their homework til kingdom come, ensure they're getting the best nutrition, read to them every night, and spend hours trying to figure out what to get them for Christmas, but when it comes to how Mr. So-and-So has it out for them or how they were the only one not invited to X, the INTP parent is liable to tune out or just give a rational dismissal of said emotional issue.
I've ran into this problem a lot with friends.
Them: "I just...I don't know what he's thinking, you know? It's so frustrating and sometimes I feel like-"
Me: "Well ask him then. Problem solved. So what movie should we see?"
And I can so easily see how it can be misinterpreted as uncaring, but I can't help it. So I think kids (and any idea of a committed relationship) are going to have to wait...a long time. Some sort of tangible sensitivity needs to be established first, and that's probably the case with a lot of this type. Because parents should be able to easily express emotional support and empathy. It's pretty important.