The city has no Zoo.
You can go to the Botanical Gardens, but they are located 15 km outside the city on the way to Makeyevka and, as cab drivers told us, there is not much to see there...
It's no trap/danger to buy fruit or vegetables on your way.
There are a lot of vendors selling their ware at the roads.
You can stop and have a snack at one of the roadside cafe and restaurants too.
Unique Suggestions: Go there in summer.
Fun Alternatives: Enjoy your stay at Shcherbakov Park.
When in Donetsk you are probably untouchable and respected by Police but a right person to treath by their power. Try to keep away from police, they're really hungry of your money, and every things they say to treath are just ***s to make you feel fear. Give them money proportional to your infraction (do it if they take too much time even if you didn't made) and they let you go without remember who you were, what you did and how much you brake the laws.
Unique Suggestions: Try to arrange yourself when something small happen (like small crash-accidents if you drive) by money without call police, they can ask you much more and take out the driving licence for nothing: The car insurance works just with police report, so if you made a damage of 50$ is much more better you give that.
Ukraine is a quiet country, no criminal and safe, but behave well and careful and be crazy only in safe places, or traps could come from everywhere outside.