Transfer Data from Nios II to FPGA using Avalon-ST

1. I see two warnings on the Platform Designer that say almost_full and almost_empty signals must be connected to an Avalon-ST sink (as seen in the first image attached). Hence I was just wondering if they should be connected.

2. Does it mean I would just write to the FIFO just as I would in the case of a simple array/buffer?

Oh I wasn't aware NIOS doesn't support streaming. Is there a documentation that says so?

Thanks for the inputs!