What documents do I need to gather for my marriage in Bangkok as a Dutch citizen marrying a Thai national?

So far, I've gathered:

1. Birth certificate

2. Extract from the Municipal Personal Records Database (this lists my marital status)

3. Extract from the marriage certificate (divorce certificate) from my previous marriage

4. Passport copies

5. Application form for declaration of marital status with the intention of getting married in Thailand

6. Witness and income statement

I'll have documents 1 through 4 legalized in the Netherlands at my municipality of residence and then at the Consular Services Center of the Ministry of Foreign Affairs in The Hague.

I want to take them to the Dutch embassy in Bangkok for legalization there, and then to the MFA in Bangkok.

My concern: should I have my passport copy translated in the Netherlands by a certified translator, have the translator's signature certified by the court, and then by the Thai embassy in the Netherlands? (That's what I'm reading.) Or is this done in Thailand?

And furthermore: how do I prove my income? I'm self-employed, not employed. My income is high enough, but how do I prove it?