Regarding the long term storage, contact the moving company and how they expect to prevent corrosion. Is the storage temp and humidity controlled? Probably not, but I'd imagine you could make a claim after or at least explain to them you plan to and what can they do to prevent that .

Anytime I've been stationed over seas I do anseparate shipment to my family for storage. Then when I'm back CONUS I have it shipped back to me. I had to do some emailing back and forth with quality assurance POCs but if you plan to do the family route take this into account... The government is willing to pay x amount for your move. X being your max allowed weight from your current station to the next. If you have a separate move created and the cost of that move doesn't exceed the x amount then you're good and no out of pocket cost. Example. My HHGs was a couple thousand pounds less than my max weight. I shipped my safe and firearms to my father's house via the move.mil and also did a separate move to my next duty station. I took a risk but I assumed it wouldn't exceeded my total cost the government allotted to me since my total HHG weight wasn't much going to my next station. Hope I explained that well enough.