Controversial issues and their resolutions.

Question: Is it possible to use Flight and Chain Lightning if the maximum guild level is only 3?

You answered this question yourself in your post. The rules allow the use of both the Flight scroll and Solmyr's Chain Lightning if Guildhall 5 or 4 is built, respectively. Moreover, if the castle itself does not physically allow building floors 4 and 5, then in any two built structures, build the tower to the maximum: Barbarian + Barbarian; Barbarian + Swamp; Swamp + Swamp; Swamp + Castle; Barbarian + Castle; Castle + Castle.