The carbon reed question is already answered. If starting is good, the reeds are OK

The black piston crown is an indication that your mixture has been a bit rich. It looks OK though and nothing to worry about, and it will not harm the engine. In fact, it isolates the piston from the combustion heat, and should only be slightly smoothed for best engine performance.

If you store the engine for a longer period, a few drops of oil here and there , especially the bearings and piston skirt would be the right thing to do. Normally this is done on assembling the engine, when all parts are accessible.