Learn Farsi: ویراستار دوم رو این عنوان کار نمی‌کنه. - The second editor isn't working on this title.

Yes, you can put it before! In Farsi, you have two choices for ordinal numbers like second or third. You can place the number after the noun using the -om suffix and an Ezafe, like we see here: virāstār-e dovvom. Alternatively, to add emphasis, you can place it before the noun using the -omin suffix with no Ezafe: dovvomin virāstār. Both mean the second editor.

Do I need to pronounce an Ezafe between virāstār and dovvom?

Yes. Even though it is not written out here, you must pronounce it as virāstār-e dovvom. Whenever you use the post-nominal -om ordinal form, the noun always takes an Ezafe to connect to the number. If you used the emphatic pre-nominal form (dovvomin virāstār), you would drop the Ezafe entirely.

Is ru acting as the direct object marker (rā) here?

No, in this sentence, ru (often pronounced ro) is a shortened, colloquial form of ru-ye (on). The phrase ru in 'onvān means on this title. While ro is very often the spoken form of the direct object marker rā, the verb kār kardan (to work) takes the preposition ru-ye when talking about working on a specific project or subject.

Why does the verb end in -e (ne-mi-kone) instead of -ad?