Catholic church reforms, Reformation avoided

IOTL the Reformation happened in a climate of criticism on the Catholic church that had built up during centuries - Crusades lost, Black Death, several popes at the same time (which hurt their authority), luxury of the church leaders, selling indulgences even for dead people... Luther, however, added a completely new theology, replacing the old belief "you have to do good deeds to be saved" by "everything that counts is your belief in God".

WI, let's say, the councils had been more successful, removing the worst abuses, making the pope the first among equals, and generally moving Christianity closer to the scripture (including allowing translation)? The new church could look a bit like the Hussites... What does this mean for this TL? No reformation -> no Calvinism -> no capitalism?

The Church did reform, the Council of Trent addressed most of the Protestant questions in 1542, (a mere 31 years, next day service in that era) and while the answer was the same, lofty "fuck you, heretics," that it had given throughout history on some issues it did stop selling heaven. The result was the same in any case, as Francis I did not even allow the summons to be circulated in his area.

Your scenario is same scene, different players. The northern Princes would either openly break off from the Church for other reasons or break off simply because they could. Religion at this time, (as in ours) was one of the main things Princes used to justify wars, but the Catholic/Protestant thing was brand new then, so still all shiny to most people who hadn't heard of it.

Religion was also then as now fulfilling its other function of justifying whatever we do to stay alive and Capitalism, for several reasons like improving transport and rising agricultural/industrial productivity, was just becoming practical in Northern Europe, as it had been for several centuries already in the Italian cities. It was Zwingli's genius to recognize that since Christianity forbade profit, something was needed to distinguish the properly pious Fuggers from the openly hypocritical Medici; and, voila, predestination.

Barbara Tuchman in The March of Folly argues persuasively that less "wooden headedness" on the part of the unregenerate Popes might have staved off ruin, but then seems to find that the very stupidity is itself unavoidable and perhaps we are all better off in the end.

I think the point might be that the Council of Trent (or some earlier one, to head off Luther) would come up with an answer other than "F*** you, heretics" and adopt more reforms.

And I had thought about an earlier council, maybe after a worse Black Death (let's say both concurring popes die, first, it can be itnerpreted as a heavenly sign, and second, the new pope might be more inclined to reforms. Or the cardinals decide that they don't need a pope immediately).

You need to avoid the infamous papacy of Alexander VI. if one of his predecessors (which had their own share of deficiencies) calls a council there is some possibility of just enough reform to either avoid the Reformation completely or (more likely) marginalize Luther, Calvin et al.

Tom