Millions of people have tanks with no skimmer or filters.
I'am one of them....although i am using a old AC500 as a refugium with alittle live rock and Cheato algea in it.
I also have 2 power heads, 1 tunze 6025 and 1 Vortech MP10 wES
All you need is about 10-15 lbs of live rock and live sand and plenty of water movement....and keep up on the water changes.
It's only as complicated as you want it too be.
I would only go with 1 or 2 small fish with a shrimp or 2, and the clean up crew of snails and crabs.
I have allitte bit of Marco rock if you decide to set it up...it's dry but just seed it with some Live rock and its good to go.