I don't do your text, but in terms of general brainstorming:
- "complex nature of human experiences" --> here, you can bring in the specific anomalies, paradoxes and inconsistencies in human behaviours and/or motivations that are presented in your text, and tie this with a theme. I'd have each body paragraph with a specific theme from my text as well. For instance, one of the themes in the Merchant of Venice is the paradox of justice, so I'd say smth like ... the Venetians are inconsistent with the Christian values of 'mercy' they advocate for in their prejudiced treatment of Shylock, a paradoxical/complex behaviour that stems from their motivation to rid the 'Other'. Then Id go on analysing examples from the court scene.
- "lasting impression" --> this is more sort of the effect on the audience, i.e. how the complex idea presented is timeless. So how is the complex idea presented still relevant to us now and/or encourages us to reflect personally/ challenge our assumptions? (stuff from the module statement). For example, when finishing off my para on justice versus mercy, I'd say smth like ... Shakespeare's representation of this *paradox of...* challenges our assumptions of the nature of justice as inherently free from bias / enabling us to reflect personally on the facade of fairness amongst political institutions etc etc.