Suspicion about the president’s potential conflict(s) of interest can be answered by releasing his tax returns. What is now clearly known about his personality and character (he is an unprincipled liar) leaves really no conclusion about his resistance to their release other than he doesn’t want them open to public scrutiny because they contain information of conflict(s) of interest.
I believe he is using his office to further his personal and financial interests. Betraying an ally is not treason. However, a president commits treason if he makes a decision that puts his personal interests above those of the country. His tax returns must be released and the impeachment inquiry must be completed.