When I was a kid, my dad used to take me sometimes to a street vendor (this was in a small city in Malaysia, late 60s/early 70s) who ran his business from a bicycle. He had a small gas ring, a crate on the back of the bike with a couple of chickens in it, and some veggies and noodles.
My dad would order a meal and the guy would grab a chicken out of the box, wring its neck, drain the blood into a bucket, burn off the feathers, dismantle the chook and fry it up with mein and veggies. Yum!
But after handing us our food he would boil and eat the then congealed blood (and the other stuff we didn't eat). The food was great (especially since my mum did not approve) but I was always fascinated by this last step.
As I got older I appreciated that he had us pay for the meal and then still got a meal himself out of the deal.
[Blood sausage][1] is made using pork blood. I have never tried it myself though. What I have tried is [Sanguinaccio][2] made in southern Italy. It's absolutely delicious. I imagine there are plenty of other recipes that use pork blood as an ingredient too.
[1](https://en.wikipedia.org/wiki/Blood_sausage)
[2](http://www.chicagonow.com/cooking-cop/2014/03/sanguinaccio-d...)
The only danger I am aware of--beyond the risks of eating pork products in general--is iron overdose, which means you have to ration your consumption appropriately.
The viscera may also be used, though not necessarily for food. Whatever cannot be eaten can likely be turned into glue, leather, fertilizer, string, etc.
https://en.wikipedia.org/wiki/Sundae_(Korean_food)
Pig liver is a popular in dishes the world over: pate, various sausages, etc.
It's surprising how much of a pig is useful as food.
Pig intestines, heart, lungs are all part of traditional cuisine. Even the kidneys and liver are "viscera," and those are completely mainstream organ meat. Brain is also eaten (head cheese).
Photo of making blood pudding
https://goo.gl/photos/fUkkcmUxLXmopAQf6
Photo of preparing the heart before marinating it in olive oil and spices, then grilling it.
https://goo.gl/photos/T4MQZDpyEDVLgy7o7
Photo of pressed, sliced, and fried pig ears as a side to a sausage sandwhich
https://goo.gl/photos/me1rguNxWKXrmNLQ9
Photo of head cheese
https://goo.gl/photos/kHpyoDWJRxvDgHxW9
Photo of dog enjoying pig spine
https://goo.gl/photos/Wwpf9npvyvoKiBQN8
I use absolutely everything (well, except for the intestines. Not worth my time or energy to wash the feces out and scrape the mucousal lining off).
Curious, what did you do with the lungs? That's one part that I think was commercially banned for human consumption in the USA in the '70s. Even if it wasn't, it's rarely sold fresh as I understand it does not keep well at all even under refrigeration. Pork lungs are used used in Fillipino (bopis, kilayin) and Cantonese cuisine; Europeans certainly use sheep and cow lungs (Greeks, French, Scottish; haggis, anyone), but I'm not aware of western recipes specifically calling for pork lungs.
Pork intestine, on the other hand, is ubiquitous.
I buy whole chickens and part them out myself, and I do use every bit of the chicken that comes in the package. The bones are used for stocks, skin gets rendered for fat, etc. So I like to think I (can?) get using every last bit of the animal.
But I'm curious, what use(s) does the blood have? I was of the impression that like the viscera, the blood is something that necessarily must be disposed -- it cannot safely be used. Is that not the case?