Well my wife and I eat organs and suet. Around 4 pounds of liver a week(each) id say.. she probably eats a bit more than i do, but we're not turning orange yet after months. When you've had enough liver, you dont want it anymore (which isnt much help if you aren't really keen on it in the first place, but hey..) We will eat just liver for 2-3 days while its fresh and best, then pick up our next liver the next week, so we pack back a whole bunch, then move onto our kidneys and hearts etc. and if we eat all our organs before they send in the next cow, THEN we pick up some muscle meats.
My wife eats lots of suet and she does fine on it, I personally dont find i digest suet as well, but it might be because i eat all kinds of omnivorous stuff on top of my meat(while she's carnivore).
I dont think you have to worry about 'Overdosing' on anything that you're picking up from the butchers. I would think that you will just not want to eat it anymore, long before you develop leprosy.
Although my wife had a similar experience eating a big whack of moose brain, to when she eats too much adrenal. So we figure she must have eaten the hormone glands in the brain and they sometimes make you feel like you're tripping balls and you dont know if you're going to throw up or shit yourself.