1) This question depends on how you value the coin. I’ve always valued things I buy in USD along with the rest of the world. Casascius coins are no different. So while it’s cute to talk about when to get the most BTC premium, taxes and reality would dictate you value it in USD and I’d recommend trying to get the most USD possible when selling. The number one factor in how much $ you get is the Bitcoin exchange rate and this is why peeling can be better than selling at a premium because you have more control over when you cash out and no risk of shipping.

2) I’d recommend keeping them at a bank out of state. Downsides being you’ll never see them and definitely won’t ever show anyone. You don’t want easy access to your Casascius coins.

3) Grading has historically been pretty worthless. They can’t spot fakes and their grades are all over the place. If you resubmit a coin it will get a different grade the second time. Not to mention more hands on it and more shipments is never a good idea. I am a minority in this view, but I would recommend avoiding grading.

4) Selling on the forum with escrow is the preferred method historically. I’ve escrowed dozens over the years and never had an issue, but shipping is always scary. Auction houses are also becoming a popular option, but the fees and swings in BTC price can make this option worse than just peeling.