Constitutionally, is it right for Trump to withheld documents, ordered witnesses not to testify & lawyers not to participate in his trial?

It does not violate the Constitution for him to be stupid, no.

Do you mean was it right for a person to ask to see the court warrant issued to search you?

Yes.

Every president have used Executive Privilege to keep stuff to themselves. That is completely Constitutional. However, what is also Constitutional is for Congress to go to court to force compliance to subpoenas. The House Dems intentionally CHOSE not to do this route because it didn't fit their, then, time table of needing to get impeachment out of the House and on to the Senate. Pelosi had her chance to do this during the House impeachment inquiry, she can't cry about it now.

The constitution outlines three separate branches of government. It does not put one branch as the overseer of the other. Congress has limited power over forcing the executive branch to do anything.

Any power it does have would have to be confirmed by the judiciary.

Constitutionally, it is absolutely correct for any President to exercise these powers and ask the courts to clarify, as the President has done.

Following due process is not obstruction.  In fact, failing to give any citizen due process is failing to follow the Constitution.

The House could and should have subpoenaed the desired documents and witnesses and waited for the proper court rulings to satisfy due process.  The House could not be bothered.

No, it's wrong and no other president has done it. Also, logically, it seems to indicate he is guilty and wants to cover that up.

None of that is directly addressed in the Constitution.

To order something not to do something on their own time is wrong.  The other stuff, it depends.