Looking for wise replacement intervals for drive belt, cooling hoses, and spark plugs for 2018 Rogue Sport? Thank you! Mike
most of those are inspection items. You have to assess them visually.
The belt will usually alert you when it's time to replace it because it will start to slip and squeal.
If you see it getting badly cracked and crumbly then change it. There are tools you can get for checking too.
Previous answer here: https://carkiller.com/scottykilmer/qa/ford-fusion-serpentine-and-drive-belts-replacement/
Cooling hoses .. again inspect them. They should be flexible. If they get old/stiff/cracked replace them. I don't think you'll need to worry about that for a long time. It's not like they're on a timer. You will see them degrade.
Spark plugs can be removed and inspected too. Make sure electrode isn't burnt up, and in good shape. Check the gap with a gap tool.
How quickly they wear depends greatly on how the vehicle is driven. They could be bad at 40k or they could wear out at 100k. See your owner's manual maintenance schedule for details.