My goal is maximum preservation and presentation. Something that will last forever and look amazing.
Nothing lasts forever. But if the rest of your lifetime will do you you're in good shape ;-)
Wood by itself can be pretty surprising in how well it lasts indoors, look at the structural pieces in the attic of almost any older house for an example. And that's with nothing at all applied to it and regular baking during the summer months and freezing during the winter. Add some finish, and a certain amount of ongoing care, and something made from wood can last and continue to look good for generations as many heirloom furniture pieces demonstrate.
After cutting the wood and I have to seal the ends immediately.
You don't have to do this with branches and slim saplings, they're commonly dried just as they come from the woods, sometimes even with the bark left on. And contrary to the usual advice for wood converted to boards, they're frequently dried upright and not laid horizontally1.
What should I use to seal and where do I go from there?
If you do want to seal the ends there's no one thing you must use, but the best thing for the job is melted wax. Any wax will do, including that from cheap candles if that's all that is available.
Remember that sealing the end grain is to slow drying, so this automatically means you have to wait longer for the wood to be ready. Much stick material is dried without the ends being sealed partly so it doesn't take as long, and slim stock 'in the round' like this just doesn't crack as much as much thicker stuff.
How long should I leave it to dry (I have plenty of time - is a year to dry the optimal choice for a display staff and cane?).
How long is a piece of string? The wood dries until it's ready to use, and how long that takes depends on all the possible variables.
It's rare that patience isn't rewarded when drying wood, both speeding the process and using wood too early can have negative consequences. So if you can wait more than six months and as much as a year you're unlikely to regret it.
Where do I go from there?
After drying, cutting to length and any shaping or smoothing work you want to do the wood is ready for finish.
For a finish you can use anything you want, literally anything you've heard of used in wood finishing will create a shiny surface. Shellac or oil-based varnish are good choices as they aren't expensive, are commonly available and easy to apply to a high standard, and additionally they're both longer lasting than lacquer so I'd pick them in preference.
And what maintenance does it need to last forever?
Regular dusting is the best thing you can do for wood as ongoing care, and the occasional wipe down using a damp cloth can be beneficial if required. With periodic waxing2 to help protect the surface of the finish you could typically expect any finish to last many years.
Beyond that possibly refinishing every few decades, but the finish used and the environment dictate how well a finish endures. Note that shellac is much easier to top up, or remove and replace, than varnish if ever needed.
1 Don't know why, and I don't know whether it actually makes a difference.
2 NOT oiling. Avoid all oil-based furniture polishes.