Yes! Sort of. Testing on an 8GB Model A with PaperMC, User:CounterPillow was able to out-row world generation in a boat with just one player online, but aside from the slow world gen (which can be pre-generated) the server handled things like TNT explosions and mobs fine. It’ll probably do okay with 1-3 players.
You only need the 5A power supply for Model A if you plan on connecting hard disk drives to the 12V header on the board.
For Model B, it’s <2W in idle (powertop tunables not set), and <5W under full CPU load (
stress-ng -c4). Model A will be similar as it’s the same SoC.