I have a problem with Liverpool also there. They were only able to qualify for last 16 the last time. But still they are the biggest favourite.
PSG should have been favoured more than Arsenal... I mean they became champions and eliminated Arsenal in the semi-finals too.
I agree with your opinion on Barcelona and Newcastle as well. It's unreal Newcastle are ahead of all those teams.
Yes Liverpool looks a bit strange but this is just the bookmaker’s opinion nothing more. I would place Barcelona above Arsenal and Real and I would also put PSG above Real but there is no problem if for example you think Liverpool is weaker because it actually gives a better odds for choosing Barcelona or PSG as the next champion. I doubt that Liverpool is capable of winning the Champions League and I also have doubts about Real because it is unclear how they will play under Alonso. I am not fully confident in Arsenal either they always seem to be missing something but the next four teams in my opinion are quite capable of reaching victory.