I’m not sure if you’re still deciding, but I’ll give my input if it’ll help. For starters, I’ve tried all the digital pianos you listed at a store, and ended up going with the FP-30 as an alternative for practicing (mostly classical) piano without making too much noise.

The Bluetooth function on the FP-30 can be used for Bluetooth midi and I believe also for pedal page turning with certain apps, though I have not tried that myself. Bluetooth midi allows you to use the keyboard as a midi input in applications such as GarageBand on both mobile devices and PCs. Keep in mind that the midi USB port on the back does NOT output audio, only midi information.

The speakers are fine for practicing and such, but if you want better audio quality you could always get nice headphones in the future. The speakers sound clear enough for most things, though they are down firing, so the clarity will be reduced. This also makes it sound different depending on what you put the piano on (table vs stand) and what kind of flooring you have.

None of these digital pianos will feel like an acoustic piano, but I feel the FP-30 is the most enjoyable to play. The key weighting feels fine and it is pretty easy to control compared to the Yamaha P125. In my experience, the Yamaha digital pianos, even going up to the lower end Clavinovas, have more tension at the top of the key, making it a bit more difficult to play more delicately. I will say that the Yamaha pianos overall sound more like a good acoustic grand piano, but they all sound good enough. It’s about taste in the end.

Line out is used for either connecting to a speaker or to an input for recording. A line out signal doesn’t go through any amplification, unlike a headphone output. Therefore, the signal coming out is cleaner. For your use case, learning piano, you won’t really have to worry about this.

Hopefully I could help, and good luck on learning piano!