Your statements are reasonable to me. It is clear that Real Madrid are the favourites to go to the semi-finals, but football can be unpredictable, which also means that Bayer Leverkusen could pull a surprise. Neither team was fantastic in their second-round wins. Real Madrid struggled to beat Juventus while Leverkusen was lucky to win over Monterrey. Real Madrid and Borussia Dortmund met twice last year and the Spanish side won in both encounters. But if Niko Kovac's side can avoid mistakes and play with confidence, the result might be different.
You seem to have gotten something mixed up. Bayer Leverkusen is not participating in the Club World Cup at all it looks like you confused them with Bayern. And Bayern did not beat Monterrey they beat Flamengo, while Monterrey defeated Borussia Dortmund. In general there is quite a bit of confusion around this.
I agree that Real should beat Borussia Dortmund. They have done very well in the transfer market, and are clearly stronger now. Their defense has been reinforced, and several defenders have returned to training after injuries. I do not know if Carvajal and Militao will play, but they are already back on the bench. So yes I agree, that Real should defeat Dortmund. As for Bayern I think it is going to be very tough for them against PSG, and I am not sure if they will be able to beat them.