I've had to go through the process of sorting through someone's stuff and financial affairs after they passed away, so from someone's who's been where you kids might potentially be one day...
The people you leave behind will be grieving. People don't think clearly when they're grieving. Don't try to be too clever or someone will skip over a step in your cunning plan by mistake, everything will get confused and they'll give up or let someone else deal with it. You can't get out of dying, you can't avoid the practicalities that come with it and the people you leave behind will end up resenting you for making your affairs difficult and overly complicated to deal with.
The government doesn't actually get that involved with deceased estates and there's plenty of room to deal with things privately. The tax treatment of inherited property is really quite favorable, so it would be worth doing some reading up on it, or seeking professional advice. You can describe your stack as "personal items and valuables" when talking to a solicitor and that's a generic enough term that they'll be able to give you advice on how to make arrangements without you giving away too much detail. You could talk about watches and jewellery instead if you like and the advice will be be equally applicable. They'll be used to talking about small, valuable heirlooms that are usually kept hidden away in a safe place.
In my humble opinion, the biggest risk to your estate shrinking isn't the government, it's that parts of it it won't be found, will be disposed of badly if it is and/or your kids will fritter the money away on stupid stuff (on one hand they're entitled to do that but, on the other hand, it's a terrible waste of potential). People are generally pretty bad at assessing risk so try not to get too hung up on remote possibilities. Okay, shit happens and it's possible you'll get hit by a bus or something but, for example, the leading cause of death for Australian males aged 25-44 is suicide (and, therefore, I am actually my own worst risk). Have a plan, keep it simple, don't stress.
Your executor is legally able to sign off on stuff to do with your estate, but that doesn't mean they'll actually be any good at administering it. There's a shedload of paperwork involved and dealing with it takes time. Mistakes can be made, some things might not get followed up on, the executor has their own life to get on with, etc. Try to make their job as easy as possible because they're doing you a hell of a favor. Keep a list of bank accounts, life insurance policies, share trading accounts, unallocated metal accounts, etc. - anything that you wouldn't want excluded from your estate and assuming it's being managed by someone who's grieving, stressed, a little bit out of their depth and pressed for time.
If you have different instructions for how your kids' inheritance should be handled before and after they turn 18, have a pre-18 will and write a new one when the first one turns 18 and then rewrite it again when the second one reaches 18. It's more work, it's a pain in the arse, but administering your life is an ongoing process so you can't really just "set and forget" if circumstances are going to change.
Yes, you can bequeath "the contents on my safety deposit box to my son Jack, including the personal effects and papers therein to be dealt with by him, alone, as he sees fit". Most people will assume it contains evidence Jack was secretly adopted or there's photos of an illicit affair you had with a circus midget, but they'll understand it's private and leave it alone.
Some things you might want to consider:
- Having an enduring Power of Attorney/Living Will drawn up in case you get hit by a bus but end up a vegetable rather than six feet under. It happens and it's actually a worse scenario than you being killed outright for everyone around you (believe me) because they can't really grieve properly if you're brain-dead and hooked up to a ventilator. Maybe think about asking to be kept "alive" long enough for the doctors to find new homes for your organs and then let your family pull the plug and get on with things. Personally, I reckon that's a pretty decent thing to do on your way out, but think about it and talk to your family about it too - they'll probably have to give the word before they get a chance to go through all your paperwork and there's no benefit to anyone in keeping your organ donor status a secret.
- Having enough low-premium stuff close to hand that selling it at spot minus 5% tomorrow will pay for your funeral. Taking $5k or so off the bill will be a huge weight off whoever is left behind if money is a bit tight for them and having a million dollars tied up in probate for six months is nice but not helpful when they're trying to pay an undertaker. You might also consider keeping the "burial fund" as cash or in a bank account that your kids or executor can access quickly and easily, such as a joint account that you agree won't ever be touched unless you die, but that's different kettle of fish.
- Writing a letter to your kids and keeping it with the stack explaining what the stack is. If they don't know what it is, the first thing they're going to think is "This is mum's/dad's old coin collection. Maybe it's worth something..." And then they'll take it off to a coin dealer who makes their money buying deceased estate lots for 10c on the dollar. Explain how to find/calculate the spot value of the items so people know (roughly) what the floor price should be so they won't get totally ripped off when disposing of it, but also try to describe or list the contents and explain the difference between:
- Generic, low premium stuff
- Rare, high premium stuff
- Novelty stuff you bought just because you like it
Offloading the stuff with a 300% market premium for spot would be a shame (not a total loss, but if you can give people some guidance, do).
- A note, kept with your stack, giving this forum's URL and your username (you might not want to state your password, but there have been a few cases where a member here has passed away with trades pending, so being able to get access to your PMs might be useful - the admins might have some advice on how they deal with these situations).
- A note, kept with your stack, with contact details for forum members you trust to offer free and frank advice or assistance for someone who needs to offload your stack if you're not around. Again, there's been a few cases where people have sold deceased estates here and the forum members have generally been really helpful and shown a lot of goodwill in getting it cashed in. For what it's worth, I have reciprocal arrangements with a few people here who will help my family sell my stack and me theirs if one of us kicks the bucket. We just have notes left behind saying "In the event of my untimely demise, call XXXX on XXXX and they'll help you take care of things" and a few other details. You might agree that these people won't actually buy any of the stuff themselves so there aren't any conflicts of interest, or at least that they'll match or beat any fair market offer if there's one or two items that they do particularly want themselves.
- Educating your kids about precious metals (pretty self-explanatory).
- Talking to your kids about death and dying. Yeah, it's a bit of a downer, but it's going to happen anyway so you may as well take the opportunity while you're still alive to talk about it and what you hope will happen to you and your stuff. And them as well. Their lives are probably pretty important to you as well.
Hope that's helpful.