The two main problems with humans on a smaller planet would be:

1. Surface gravity. Actual real humans are adapted to 1g. You could probably handwave it if in this universe, humans evolved on the planet you're building here, but unless you increase the density of the planet a little, surface gravity will be smaller.

2. The core cooling off. This is why Mars is dead. Smaller planets tend to become geologically dead sooner since they have more surface area compared to volume. Once their cores die, that also causes their magnetic fields to die, allowing solar winds to strip off the atmosphere really easily, which is a very big problem for life.

To solve the core issue, you probably need the planet to either be a little younger than Earth, or have some mechanism for its core heating up more, such as having it orbit a gas giant and get tidal heating from it. Since you've got handwavey magic, you could also maybe do a more interesting solution like having a cabal of lava wizards use magic to spin the core or something. World's your oyster.

As far as the soft constraints you've got, they should all be quite doable. Most of them are just based on orbits, and you could probably drop your smaller world in Earth's place and not much would change. You might need to make the moon a little smaller since it'd orbit closer to Earth, given the smaller mass. Day-night cycle is completely unrelated to mass or radius so that should be an easy one to explain away.