Indeed, studies suggest that only about 30% of people are particularly susceptible to the effects of dietary cholesterol on blood cholesterol levels.
These US government dietary guidelines (page 76) suggests it is safe to consume <300 mg (a little bit more that in 1 egg) of dietary cholesterol a day.
Which of these options are scientifically accepted? And is there any contradiction in these three different viewpoints?
This meta-analysis from 1992 by Hopkins of 76 trials where food was supplied by a metabolic kitchen nicely answers this question. [1]
The rise in cholestrol on consuming cholesterol is closely tied to the baseline consumption of dietary cholesterol. So, you can see that if you're on a plant based diet ( or vegan ), with zero cholesterol intake, then consuming an egg containing 250 mg of cholesterol will raise your serum cholesterol by about 0.35 mmol/L (13.5 mg/dl) but if you're on an average american diet of 400 mg/day of cholesterol, then the rise is only 0.1 mmol/L (3.9 mg/dl). This is the reason why many studies were confused by the effect of eggs on dietary cholesterol as they didn't understand the relationship between baseline intake and added consumption.
I haven't read link 3 above, but usually dietary guidelines advise that you don't exceed your cholesterol intake by 300 mg/day but they do not advise that you should consume cholesterol. There is no biological need to consume cholesterol since we manufacture all of our requirements in the liver.
[1] Hopkins PN. Effects of dietary cholesterol on serum cholesterol: a meta-analysis and review. Am. J. Clin. Nutr. 1992 Jun;55(6):1060-70. PubMed PMID: 1534437. Full text
