Thank you for your answers Corey.
I agree, I already used insulin sparingly, ramping up to a maximum of 15ius per day, but I want to learn more so I can make a better use of it.
I feel pretty safe, as I hardly put on bodyfat and I can eat a ton of carbs to avoid going hypo (I use dextrose with insulin, 10 grams or more per unit); I'm using Humulin-R and I never go to sleep before 5 hours after taking it.
How can I know if I'm becoming insulin resistant?