What precedents are being violated?...& precedent means nothing in your profession ? You see no long term implications or opportunity for abuse ?
As I have gassed on about previously, the reason for the House votes in the Nixon and Clinton cases was because (under House rules then in effect) such House vote was necessary to authorize subpoenas issuing from the committees. Under long since changed House rules, the committees now in action have standing power to issue subpoenas. So there is literally no reason to have a House vote now.
Also, in the Nixon and Clinton cases the House activities were preceded by extensive special counsel, independent counsel and grand jury investigations. ALL of those investigations were conducted in secret. In the Ukraine affiar, the investigation is being done directly by the House. So logically such House investigation should be in secret. Side note -- the Nixon and Clinton investigations (including grand jury materials) were delivered in full and unredacted to Congress. With Mueller, not so much.
Under the Constitution, impeachment articles consideration, impeachment trial and all votes and proceedings would be public proceedings (and would be nationally televised). Per the Constitution, CJ Roberts would be in charge of the trial and Senate rules (controlled by the GOP currently) would govern. This will be as public as anything could possibly be. And as fair to Trump as could possibly be. Although I thought the Clinton impeachment had a weak basis (as confirmed by the bi-partisan Senate votes which cleared Slick Willie), I don't recall the actual house and Senate proceedings as being unfair. Mostly I recall the gold stripes on Rhenquist's robes more than anything else.
So what precedential issues do you see, Salty?
To me, the Trump proceedings so far seem just fine. And as well or more grounded than the Clinton proceedings.