They could have suspended the impeachment trial and created a select committee to gain more information about what really happened in the insurrection. This would have freed up the Senate to tackle all the other things.
Remember: Ds control the Senate. We need to do so. McConnell did not allow the impeachment to be transmitted to the Senate while he was still Majority Leader. And then yesterday, he claimed that the trial was "unconstitutional", even though he is the one that allegedly made it "unconstitutional." Under these circumstances and trump's complete failure to abide by anything the House wanted for the last 2 years, suspension of the trial and creation of a Senate select committee was entirely warranted.
And the Senate could pass all the other things you reference during the suspension and while its select committee was gathering evidence.
The Senate called witnesses during the Clinton impeachment. Ken Starr called Secret Service agents guarding Bill Clinton during his criminal investigation. There is no way that a five day trial could cover what happened during the insurrection, and MANY questions are left unanswered.
The impeachment proceedings into the insurrection was NOT a "useless principle". Even if it would not have changed votes, it would have kept the matter before the American people and helped get to the root of what really happened. The Senate agreed to allow witnesses, and then no witnesses were called. Do you think that's ok? Don't get me wrong: the House Managers were brilliant. But they had limited evidence, because trump and the Republican Senate majority effectively prevented them from getting at that evidence. That's why witnesses were so important, as it allowed the possibility of getting more information (e.g., did Trump give specific orders for the insurrection, what is the real relationship between the Proud Boys and trump, etc. etc. etc.)
We may never know that now. It's like the Senate Watergate Committee leaving it at "well, these were Nixon's folks, so he's responsible, so that's that." It took multiple strands of pressure (Congressional and judicial proceedings) to get at the truth of what happened.
Look at how long the Rs dragged HRC through the coals on Benghazi. It wounded her badly. But with the insurrection, we have a five-day trial and no witnesses. That doesn't seem right.
Getting the Representative's statement into the record was no big deal. The House Managers could have done that on their own. They were routinely referring to newspaper articles etc during the trial. I don't see getting Herrera Beutler's statement "into the record" as any big deal personally.
Our nation is at death's door on many fronts. We elected Biden because we know he is capable of doing multiple things to fix the multiple failures. So can the Senate. And they need to play hard ball on EVERY one of these issues.
This article from Roll Call says it better than I can (and the fist-bump picture is nauseating): https://www.rollcall.com/2021/02/13/trump-acquitted/ . My teen-ager just let me know that "#trump2024" is top-trending. That's why this principle is not ridiculous.