]To be honest,I had the impression he quite liked and even respected Lizzy, at least as much as he respect any person.

...that Wickham enjoyed talking to Elizabeth because he detected and respected her intelligence. But I also think that, no matter what the circumstances of Elizabeth's fortune were, Wickham would not have been happy with Elizabeth because he needed a woman who would adore him for his outgoing qualities of looks, social nature, etc. Elizabeth was good to converse with, but I can't see Wickham going beyond that point in his thoughts towards her.