As far as I understand, this is actually a myth - at least the first two. It's a common cynical refrain that the current level of abundance would be impossible without slavery.
There are many many places where there has been slavery throughout the years, and they have not ended up richer for it. The American South, where slavery was more prevalent, is poorer than the North. Brazil, who imported double the amount of slaves as the US, is poorer. Northern Europe, not known for their abundance of slaves, is wealthier.
Similarly with colonialism - that's something that is only possible once your society is already rich and powerful enough to go around and dominate others. Colonialism was not a huge success for England when you look at how much it cost. It was great for national pride and as a symbol of their "greatness" however.
Cheap imported labor can definitely help parts of an economy - but remember that many people lose their jobs when labor like that is imported - not necessarily granting them upward mobility, and the ones from whom the labor has been imported are more likely to be better off than they were.