Can I connect two of them in parallel to get more power?

Sorry didn't found the documentation about this module.
Does it work as an uninterruptible power supply, i.e. it was running in "Charge and discharge" mode, the battery is charged, and the the source goes lost.
Does it go automatically to "Discharge only" and are there a delay between modes?

thank you

Does it switch seamlessly between voltage in and the battery? I.e it won't temporarily turn off if I connect a charger?

Sorry we could not clearly understand your question, this module does not have the USB output interface.