I agree with most of that with some reservations.
I agree that the authors didn't intend for a minority to be able to indefinitely frustrate the will of the majority, but neither did they intend for Congress to function on the basis of pure democracy. They intended to create a Republic governed by the people through their elected representatives, but not a pure democracy which IMHO is one of the least desirable forms of government.
The checks and balances built into our original Republican form of government have been altered over time more than I would have liked, for one example the 17th Amendment that took away the power of state legislatures to elect US Senators. I think that in the overall picture unlimited debate in Senate proceedings is beneficial in many instances and probably necessary to maintain a Republican form of government in which the will of a sizable minority of the people at large can't be easily steamrollered by a relatively small majority.
Oh... I whole-heartedly agree. It's our only defense against the tyranny of majority-rule.
The problem is this, to function properly, appointments need to be confirmed or denied in a TIMELY manner. Logistically, it is a problem when scores of courts are closed because they have no confirmed judge. The Democrats in the Senate had begun to abuse this privilege (and, to be fair, so were the Republicans) and the result was a dysfunctional court system.
I believe... a majority vote is a sufficient "check" on the Presidential power of appointment. If the executive appoints a truly unqualified person, his own party statesmen in the Senate will (hopefully) do the right thing and stop it. Winning Parties, in my opinion, HAVE THE RIGHT to put their OWN people in appointive positions... barring some extraordinary disqualifier, which a required majority confirmation should prevent.