Uruguay is significantly safer than say Rio, but again, depends on the neighborhood.
I have some farms by Libertad (search it on google). Nice little town and only one bus ride from the capital. It is in the Dept of San Jose. The Dept of Canelones is, in general, much poorer. I would encourage you to live closer to the capital and in a less poor area, though I am unsure of Santa Lucia itself. I can tell you that you can get good land there for less than in San Jose or some other areas along the coast, but land prices have been going up everywhere down there. If you have the funds to get into 'industrial ag farming' of crops like wheat and soy, I can help you get started. Plan on at least $10k USD per hectare (2.47 ac) to acquire land, plus maybe 20% of what you buy as 'seed capital' to start planting etc. You would not want to start with anything less than say 25 hectares to make it make any sense.
As to what to do, well, Uruguay is primarily an agricultural country once you leave the capital. If you have an interest in wine you can do that, or I can line you up to buy a blueberry farm if you want. Or kiwi's, olives, oranges, etc etc.
I believe Uruguay could use a good lower end restaurant that caters to food of a more spicy nature, since food overall there tends to be rather bland.
If your spanish is good, you could open a small business somewhere in the capital, as that is pretty much all businesses -- small business. I imagine a good bakery with a variety of good tasting breads would do very well.