Decoupling Capacitor Calculation
The input Capacitor should not be a critical value component. The datasheet recommends a typical value of 4.7uF, but others may be used. Since there's a lot of 10uF/10V around there, they may used one on this pin too to reduce BOM items.
Again, seems to be nota a critical value, just a pull-up resistor. Those usually range from a few Kilo-ohms to hundred ones. The 100k value appears in the 9.2 Functional Block Diagram on the datasheet.
Certainly it's a clock. Its role you will need to find in the datasheets of the components involved. Given the pin name of the TDA19988, I would guess it is only some kind of system clock for it.