Learn Spanish (Latin America): ¿Qué deberíamos decidir respecto al desarrollo económico de la ciudad? - What should we decide regarding the economic development of the city?

The set phrase for regarding or with respect to is respecto a. However, because the following noun is masculine singular (el desarrollo), the preposition a and the article el must combine to form the mandatory contraction al.

Could I use en cuanto a or con relación a here instead of respecto a?

Yes, they are almost entirely interchangeable here. You could safely say en cuanto al desarrollo or con relación al desarrollo. Respecto a is great for pointing back to a specific issue that needs addressing, while en cuanto a is often used to transition to a new topic.

Is there a difference between respecto a and con respecto a?

They mean exactly the same thing and are both widely used. Adding con to make it con respecto al desarrollo económico is perfectly correct, but simply saying respecto al is a bit more direct and equally standard.

Why use the conditional deberíamos here instead of the present tense debemos?

Using the conditional tense softens the verb deber. While debemos decidir sounds like a strict obligation meaning we must decide, deberíamos decidir sounds more like asking for advice or discussing ideal plans, meaning what should we decide. At the B2 level, using the conditional to soften requests or suggestions is a key conversational skill.