WD 40 cuts the normal, non corroded deposits. On some engines I have pulled the gas intake off and filled the bowl with WD-40, cranked over with the choke on to saturate the interior of the carb, let is sit an hour and start with a quick shot of starting fluid. I have not tried this on my EU2000i as have not experienced a problem yet. Of course, this will not work if corrosion has set in.
For stabilizer I have been using Stabil, first the red and now the newer Marine blue stuff. I put in all of my equipment by always including in the 5 gal can fill ever time, (store 35 gals for the winter generator use), boat 200 gals, and summer use Ranger PU. I use the mixture on the label for long term storage, so far it has worked very well. As well ---- anything that has a shut off valve between the tank and carb gets shut off and run dry. The EU2000i has a tank vent shut off that, when new, allowed me to run the carb dry. The last 6 yrs or so vent must be leaking by a bit preventing the vacuum generation needed to run the carb dry so I have been storing wet.
I don't run periodically just to move gas on anything, and have not had any problems.
One other note, I fill all cans/tanks/equipment/boat/truck before storage. The lack of air in the fuel tank prevents any possibility of condensation on the tank walls which will contaminate the ethanol based gas.