Brad Saucier

You should be able to control everything from MIDI if you can sort out the MIDI implementation manual section about DSP parameter control. https://www.casio.com/content/dam/casio/global/support/manuals/electronic-musical-instruments/pdf/008-en/c/CTS500_S1000V_midiimplementation_update_EN.pdf

Another option would be to record the MIDI output of the Casio with the DAW software as it plays back, so you can create quantized tracks.

That's called MIDI sync. It requires a MIDI device to be set to slave mode. Unfortunately the CT-6500 does not have this feature. It's not something typically found on arranger keyboards. Drum machines however, yes it's a common feature on those.

Yes, but not directly since the level may be too low. A mic plus a mic preamp of some type, like a smaller mixer would typically be used for this.

You can turn off local control in the MIDI settings.

One way is to record a rhythm to the system track of the MIDI recorder, then save the MIDI recorder file to USB flash drive in SMF format.

External speakers can be used with the piano, however Bluetooth is not recommended since they produce a delayed sound. Pressing a key on the piano would result in hearing the note a moment later, not good for a musician. For this reason, you won't find a keyboard with Bluetooth output to external speakers. What you can use is the LINE out left and right with a cable to some external monitors. Choice of monitors will depend on budget and your needs. Personally I really like home studio monitors. Some good budget options are out there for that.

I read the blog. It sounds like you are definitely enjoying the Casio! Sweet. I'll add a note, SFZ is short for Sforzando on certain tones.

Do you have another phone or tablet you can install the app and try it with? Or uninstall the app and reinstall it on the same device.

Press function>keyboard>kbd setting> set touch response to light. This should help you reach max velocity and help you find a balance you like. I like to use the sports analogy of hitting a baseball with a bat. Key velocity is about following through the strike with speed, not so much shear force or pressure. With a little practice keeping this in mind, it's much easier to reach full velocity.

The reader slot may need cleaning. Try blowing it out with some air first.

The USB connection on the PX-S6000 can work alongside other MIDI devices connected to the computer. Your software would just need to be configured to use the Casio USB MIDI as the input source wherever you need it. It shouldn't make any noticable difference in latency. For audio, the PX-S6000 is analog output and input, so it's not going to be a source of latency itself.

I've tried looking for an answer. Unfortunately I'm not finding enough information to say for sure. Is the phone connected by Bluetooth audio as well? Perhaps try turning that off if so.

Yes I think it means overdub with new tracks.

Yes it should display like that. Click the share button on YouTube and copy the link, paste it as text here. The link should turn red and embed the video automatically.