I'm British and don't think Boris is very smart. I assume you don't take Trump to be a very stable genius! I'm just asking how Ukrainians/Russians/Those who know him as a politician think about him. The same way you would ask how Schwarzenegger or Raegan were as governors of Cali.
He could be a meme in Ukraine for all I know. (hence the question!) Is he taken seriously, or a complete plonker.
The examples you're citing involve domestic perceptions without the added variable of an impending attack from a foreign country, which is the sort of thing that tends to make people pay attention to what their local politicians are saying, and transcends the usual, pedestrian criticisms of politicians not delivering on their policy platforms. As for Klitschko, there is a recent poll that suggests he is more trusted than Zelinsky in the capital of Kiev.