If I was Transported back to pirate times. Could/Would I be able to drink that type of rum or whiskey? How powerful would it be and how dangerous would it be in today's standards?
What do you mean could would you? What is that type?
Distilled spirits are distilled spirits. They would more likely have rum or gin than whiskey. You can search the gin strength because there was a naval standard strength that easily exists today. I’m sure rum was about the same.
Gin came from the British military in South Asia. I think we can then assume that if pirates had any gin that would steal it from British ships would maintained a naval strength standard.
Otherwise rum was the drink of the Caribbean formed out of the sugar triangle. Slaves were brought from Western Africa to the new world and used on sugar plantations. That sugar was then used to make rum and played a large role in the founding of America.
I think this question deserves some sources so let’s look into it further.
Not a historian: I'm reading that rum from that time was in the range of 95.5 proof (54.6% ABV), which is not a concentration impossible to source for yourself in these times. You could try your palate on some Everclear or Spirytus Rektyfikowany if you want to try your luck with 95%. I've had both, and they are intense and liable to cure you of any curiosity.
While the most famous variety is 190, it's available at a number of lower strengths, including as low as 120. I suspect this is to allow sales in areas that have restrictions on high proof spirits.
Your warning is still valid, even on these lower strengths. Being completely neutral, it's easy to disguise in mixed drinks.