Did Christopher Columbus do all that bad stuff because that's what any other explorer would have done at that time or was he uniquely evil in his actions?

Okay, this is a good question because it speaks to the reality that Columbus was not the first explorer to discover new lands, not even the first explorer in the Atlantic.

The longer history (which is often overlooked in the usual Columbus 1492 history) is that Europeans particularly the Portuguese and the Castilians were already active in exploring the Atlantic well before 1492 and their efforts there shaped how Columbus approached his plans and actions in the Americas.

So the two precursor explorations were 1) the conquests of the Canary Islands 2) Expansion (conquests?) along the African coastline. One could add that before 1492, Aragon had crafted its own empire in the Mediterranean through oversea conquest, but that history often gets overlooked even though it is why Naples and Sicily were part of Spain for centuries.

What did those conquests set up?

The Castilian conquests of the Canaries particularly the campaigns waged in the 1400s set up prototypes for how Spaniards would act in the Americas. These were largely privately financed (just like Columbus and later conquistador campaigns). They tended to target populated areas and force them into vassalage. When those groups resisted they would be enslaved. After conquest, the local population was required to pay tribute and provide labor through some arrangement be that formal slavery or some other type of coercion. The Canaries became provisioning grounds for fleets that would eventually cross the Atlantic and one of the first sugar plantation zones in the Atlantic world (this would happen in other Atlantic islands like Madiera and Cabo Verde)

Portuguese expansion along the African coastline was less interested in territorial acquisition (although they did this in Cabo Verde, Sao Tome, and later in Angola/Luanda) than establishing trading relationships. Yet, notably during the earliest years of expansion (1430s-50s) they did engage in slave raids of groups along the coast. By Columbus' era, the Portuguese pattern was to establish friendly relationships with rulers along the coast, build up trading relationships, use the profits from voyages to finance further voyages along the coast, establish new trading relationships, rinse and repeat. Now many rulers did not participate in any trade, some participated very willingly, others participated in more limited ways. The conquests of Cabo Verde, Sao Tome, and later Angola, gave Portugal safe ports near their African trading partners to use to and from Portugal.

So what did Columbus want to do? He wanted to follow the Portuguese model. His plan certainly on the 1st voyage, and certainly for a while, was to establish factories (trading posts) that would house a small residential European population. It could store European goods that would be traded and then house the local goods that were acquired. Yet, that didn't end up working? Why?

He was expecting to find more material goods desired by Europeans. Africa had gold, ivory, and enslaved persons for export. They knew Asia had lots of precious spices, silks, and other luxury items. He expected to find more stuff. But Hispaniola and the Caribbean didn't have much they wanted. Very limited gold, not many natural products that Europeans desired, at least initially, so his plan of setting up trading posts like the Portuguese quickly made little sense.

So what could he do to make money...he needed to make money because he had investors he had to pay back.

He did what Castilians had already done in the Canaries and the Portuguese in Africa, raid for stuff. He could raid for the small amount of gold used by Tainos on Hispaniola, and he could raid for people. There was a market for people already in Europe. Enslaved people from Africa and the Canaries were already being sold in various cities including Lisbon, Seville, Valencia, and Barcelona. Nothing he did on Hispaniola, or in later voyages elsewhere was new. He did what generations of Castilian, Portuguese, and Aragonese 'explorers' had already done in the Atlantic Islands. He capture people and sold them to make a profit. He tried to use enslaved peoples and the profits off the sales of other enslaved people to set up estates in the Americas. Even though he would be arrested for his treatment, the other early participants in the process did the exact same thing. By the 1520s, Hispaniola was full of sugar plantations and placer mines all full of enslaved Native Americans and Africans.

So why did Columbus get arrested? Well, it was mostly politics. Yes, he was reported by others including clergy for his violence toward indigenous people (violence similar to what happened centuries later in the Belgian Congo), but in many ways that ended up being a pretense for a renegotiation of political power. Columbus' initial agreement with Isabel was predicated on finding Asia (the Indies), but as we know, and as many certainly guessed by the late 1490s, what Columbus had found was not that (arguably no one ever believed his claims because his math was so preposterous that it could not be correct). What the monarchy wanted to was to revoke the very broad powers that Columbus held so that they could appoint new officials and bring the process under greater royal control. His violence toward native people offered the ideal cause to restrict his powers. In the long run, he and his children continued to fight with the monarchy for DECADES over how much of his initial contract needed to be honored. In the end, his heirs retained a few noble titles and some prerogatives, although he never saw a clear resolution to the issues. This helps explain why the violence he perpetuated was continued by others who rarely saw the same royal interest that he did. He was targeted precisely because he had too much power (by royal contract) and was behaving in ways that could easily be censured (even if they could just have easily been overlooked).

Some references:

Fernández-Armesto, Felipe. Before Columbus: Exploration and colonization from the Mediterranean to the Atlantic, 1229-1492. University of Pennsylvania Press, 1987.

Wilson, Samuel M. Hispaniola: Caribbean chiefdoms in the age of Columbus. University of Alabama Press, 1990.

Stone, Erin Woodruff. Captives of Conquest: Slavery in the Early Modern Spanish Caribbean. University of Pennsylvania Press, 2021.

Now were other European powers any different. Not really. In what would become the US, English settlement in North America is often presented as different from the Spanish, but in many ways it followed similar models. Sure the English did not initially target groups for conquest, but a single violent encounter, or even just a misunderstanding frequently sparked wars that resulted in almost identical 'conquests'. In the 17th c. you have the Anglo-Powhatan wars (1610-1646) in Virginia that play out very much like Spanish conquests, up to and including enslavement of indigenous people. In New England you have, the Pequot war of the 1630s followed by King Philip's war in the 1670s again with similar outcomes.

For a unique look at the early American period by a Latin American historian see:

Cañizares-Esguerra, Jorge. Puritan conquistadors: iberianizing the Atlantic, 1550-1700. Stanford University Press, 2006.