Learn Farsi: می‌خواهم در مورد سیاست بیشتر بدانم.

dar mored-e is a compound preposition used to introduce a theme or topic. It literally translates to "in the case of" or "in the matter of". The invisible -e at the end of mored is the ezāfe, which acts as a bridge linking the preposition to the noun it introduces, which here is siâsat (politics).

Could I use other prepositions like dar bâre-ye or râje' be in this sentence?

Yes, absolutely! dar bâre-ye siâsat and râje' be siâsat both mean "about politics" and are completely interchangeable with dar mored-e here. Just remember that dar bâre-ye uses an ezāfe to connect to the noun, whereas râje' be relies on the simple preposition be to make the connection.

Why does the second verb, bedânam, start with be- instead of mi-?

This is the subjunctive form of the verb. Because the sentence begins with mi-khâham (I want), the action of "knowing" hasn't happened yet; it is just a desire. Farsi shows this by putting the second verb in the subjunctive mood, which usually means replacing the mi- prefix with be-. The literal structure is "I want that I know".

Why is bishtar (more) placed right before the verb, rather than earlier in the sentence?