I don't understand your timing argument: impeachment could not have happened before the July 25th phone call, and couldn't have happened prior to the original whistleblower complaint, which was filed Aug 12, but released Sep 26th by the White House, after the impeachment inquiry was announced on Sep 24th. Would it have made more sense for Trump to commit his acts earlier in the election cycle to better fit a narrative?
Everyone who was willing to testify to the House had done so...what could the Democrats have done, in your opinion, to make it not an issue of 'timing'? Dragged out multiple subpoena fights over the next two years trying to get the witness Trump instructed not to cooperate to cooperate? If we had been able to question those people properly then many arguments you have been making would be rendered moot.
Lastly, Trump was impeached for trying to meddle in the very election that is supposed to be arbitrating whether he or someone else gets to be the next President: can you see how saying 'let the voters decide' is like saying that Tom Brady is the best person to tell us if the ball is properly inflated.