O engenheiro estuda o regulamento antes de começar o projeto.

In European Portuguese we normally use definite articles before nouns acting as subjects (except after the verb ser). When you say a profession with any verb other than ser, you keep the article.
Examples:
  • O médico trabalha muito.
  • A professora explicou a lição.
If you used ser, you’d omit it: Ele é engenheiro.

Portuguese often uses the simple present to express both habitual actions and ongoing events. So estuda can mean “he studies” or “he is studying.” To stress the continuous aspect in European Portuguese, you can use:
  • O engenheiro está a estudar o regulamento.
Using estar + a + infinitive is the typical EP continuous form.

When the same subject performs both actions, Portuguese uses antes de + infinitive:
  • Antes de começar o projeto (Before starting the project)
Here de is mandatory. You cannot say antes começar.
If the subjects differ, you switch to antes que + subjunctive:
  • Ele estuda o regulamento antes que o colega comece o projeto.

Começar can be used transitively with a direct object:
  • começar o projeto – “to start the project.”
You only add a when começar is followed by another verb:
  • começar a fazer – “to start doing.”

Yes. You can front the adverbial phrase and use a comma:
  • Antes de começar o projeto, o engenheiro estuda o regulamento.
The core meaning stays the same. European Portuguese usually keeps SVO order, but fronting is common for emphasis or variety.