It wasn't Trump's job in July, August, September or October to hold news conferences. Rather, his job was to run for President. Trump is not beholden to the media. If he wants to go out for a steak dinner and not tell anyone that isn't anyone's business. He can hold news conferences once he is in office.
Donald Trump is as transparent as they come. He has had no problem voicing his opinion on multiple subjects, which shows exactly what kind of leader he will be. He has shown that he knows virtually nothing about the way politics work and about foreign policy. He doesn't need a news conference to prove this.
Trump is clearly not used to being spoken to critically and having his ideas and his behaviour questioned by others. This has meant that he has developed a phobia surrounding the media. In addition to waging a childish war against the mainstream media he has also chosen only to speak to journalists who he knows to be sympathetic. This means that transparency and accountability are suffering.
No, Trump's policies are not transparent. It is not clear how he will follow through on the policy or infrastructure changes that he has promised, nor is it clear what positions he truly supports given that he has significantly changed his position on topics like abortion in order to appeal to a certain voter.