You'll be fine with your luggage, just be aware of your weight allowance. Most charge for more than the first 15 or 20kg per head.
Another thing. Theft from suitcases are common in Tanzanian airports. I always use either a suitcase without zipper or wrap my bags. But you get far with just not leaving any valuables in your luggage, of course. On the domestic flights between these small airports you can often keep and eye on your bagage the whole way, so not a big deal. But this is not the case for international arrivals/departures.