For the 24V supply, a couple amp fuse should be fine. Some of the better supplies have recommended input fuse ratings, and from memory they're typically in the 1-2A range.
The thing with switch mode supplies, is due to their inherent design/failure modes, the smallest possible fuse is unlikely to prevent damage to the supply. Any reasonable quality supply will have the output overload protected anyway, plus they also cause a surge on power up, so too small fuse is more likely to cause more problems than it will prevent. The fuse is only their to prevent fires should something short out internally, by which time the supply is dead anyway.

I wouldn't personally bother with any anti-surge on a toiroid that size, unless it's causing problems. Toiroids are however where correct size fusing is the difference between just blowing a fuse, or melting the toiroid should you overload it.
If I did want to add some anti-surge, I'd fit a NTC thermistor, and parallel it with a relay that bypasses the thermistor after a couple seconds. The problem with just a thermistor on it's own, is it relies on current passing through it to keep it warm and resistance low, so when everything is sitting idle, it can cause the voltage to drop.
The problem with thermistors on their own, is if you use too large a one, the voltage drop will be larger, and if you use too small a one, you risk burning it out under heavy load.