You generally can consider moving to secondary when the fermentation has stopped. Take a hydrometer measurement when visual activity stops, and then on subsequent days until the measurement stays the same for 24 hours.
The decision to even use a secondary is arguable. If you leave the beer or cider on the yeast for up to 3 months really, the yeast continues to clean the beer or cider the entire time. If you are racking to bottling bucket anyway, and then to bottle, you will have two racking processes that will help remove any sediment.
Download a free trial of beersmith, and use the carbonation tool that will tell you how much sugar to add to the batch before transfering to bottles and capping.
My program says that for a carbonation fo 1.9 vols, which is in the middle of the recommended style which is between 1.0, and 2.8, you would add 1.22oz of corn sugar to 2.5 gallons of cider before capping.
I have had some gushers, but never a problem with bottle bombs.
I have only made an apfelwein, never a cider, but that does sound like a lot of honey and sugar, which will end up with a high og, which I don't know if safale o4 will be able to handle, ending with a high fg, and a sweet cider. If that is what you are aiming for, go for it and enjoy.
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