I don’t see how it is self-consistent to say Sweden would’ve been more dangerous than the UK, when it is the conduct of the UK that led to condemnation by the UN and Amnesty International, and the UK is currently in the process of considering his extradition to the USA.
My own personal belief (which is merely at the level of “well I reckon“), is that he probably did the Sweden crimes, and also that the prosecution only even attempted because he was also a political thorn.
This belief is based partly on the surveys which show that an enormous number of women have been sexually assaulted and also that they don’t generally report this to the police, partly on his behaviour.
It is also partly based on the fact that — as is currently being demonstrated by the very extradition hearing currently occurring — the US is quite capable of extraditing him directly from the UK without going via Sweden.