One thing they haven't mentioned at all is risk factors. They're saying that venous thromboembolism happens as standard at a rate of about 1 in 500 every year, but those people will have specific risk factors - lack of mobility, use of HRT etc. They haven't mentioned at all whether the people who have developed VTE after the vaccine had any risk factors - ie would they be people who would be expected to develop VTE in the normal course of things, or are they considered unusual cases? I suppose they might be still in the process of investigating that, but I haven't seen it mentioned (would appreciate a link if there's something I've missed on that front).
As for the benefits outweighing the risks - for someone under the age of 50 it's absolutely not a given that the potential benefit outweighs the risk. For most people under 50 the personal risk (EMPHASIS: personal risk to the person themselves, not the risk the their relatives or people around them repeat, NOT THE RISK TO THEIR RELATIVES OR PEOPLE AROUND THEM - I will still get responses referring to this but I will ignore them as I've answered them twice here already) is extremely low, so the risk of the vaccine should be pretty much zero in order to be personally, repeat personally to the the person themselves worth it. If there is a genuine risk of a serious adverse event, even if that risk is very small then there is a judgement to be made about whether it's worth it for younger people to take on a health risk for the benefit of others (ie they will get the vaccine to prevent the spread, rather than to mitigate any personal risk). For older people, whose risk of covid is higher, the balance of personal risks is likely to more in favour of taking the vaccine (and even then depending on the actual risk, that may not be the case even for some very elderly people).
Given that many people have lost a year of their lives, had massive stress, have seen their children deprived of education and may have lost businesses and futures, asking people to take on a health risk on top of that is way way too far IMO. It should not be the case that elderly people are protected at all costs but younger people are expected to sacrifice and sacrifice and sacrifice some more. The question around whether the vaccine poses a health risk has to be answered because it's people's lives you're gambling with and it is not the case that covid is the only risk worth considering.