Learn Portuguese (Portugal): Aceitarias este risco?

To form the conditional tense of a regular verb like aceitar (to accept), you take the entire infinitive (the dictionary form of the verb) and attach the conditional endings. Here, we add -ias for the tu (informal you) form, giving us aceitarias.

Why isn't there a separate word for 'would' in this Portuguese sentence?

In Portuguese, 'would' isn't a separate helper verb like it is in English. Instead, the 'would' meaning is built directly into the verb's ending. The conditional tense endings (like the -ias in aceitarias) do the entire job of expressing what someone 'would' do.

Do I need to include the pronoun tu (you) in this sentence?

No, it is completely optional. The -ias ending on aceitarias already tells us exactly who the subject is. Portuguese speakers usually drop the pronoun unless they want to add special emphasis or clear up a confusion.

Why do we use este instead of isto or esse for 'this'?

We use este because it is an adjective that must match the masculine, singular noun it describes (risco). You use isto only for vague, undefined ideas or objects without directly naming them. You would use esse if you meant 'that risk' (associated with the person you are talking to).