Lol dude my first grow was in a minifridge just like that! I had 4 cfls "x"-shaped lighting arrangement with y connectors. You NEED ventilation for sure my first batch of plants got fried so i added a 4" inline fan it worked well.
And dont be fooled by the airtight-ness it will smell the shit...
In that little container with what looks like only an 400W light for a first time grower I'd say around 5 ounces but an experienced grower could pull out 9 ounces+.