Does mSATA on my Pavilion 500 series share bandwith with one of the SATA 3 ports?

[pddcat]

Upgrading my old gamer to do digital art. (Pavilion 500-205t) It currently has a 750 w ps, GTX 3070, 16 gb memory, an i7 4790k cpu, Blueray-DVD Burner, 2 EVO 840 125 gb SS drives and a 1tb hard drive. I need to add more storage 20+tb and

1. (Answered-see below) Want to know if mSata shares channel with one of the SATA 3 ports or is it separate? (chipset can handle 6 SATA 3 ports)

2. Do the USB 2 headers shares bandwith with the USB 2 ports on back of computer? (IE: Which are connected to the usb 3.0/2.0 hub and which to the 2.0/1.1 hub)?)

3. (Answered-see below) Do all 3 of the PCIe x1 ports have bandwith available to use with GTX 3070 in X16 port and wifi in Mini Pcie port? and if not which ones can I use?

Will be home in two weeks for a few days so I'm ordering parts and closing this discussion. Will be removing 1 tb drive adding two 14tb drives and putting an adapter on Burner to run off USB 2.0 Header. This will leave me all three PCIe 1x ports for expasion later if she needs it.

Thanks.

Update (Tom's Hardware) mSATA on this model can only be used as cache so it's not an option.

Update: From another forum PCIe X16 is 3.0 (~1GB per channel) controlled by cpu PCIe x1 and Mini PCIe are 2.0 (~500 MB per channel) and controlled by chipset.  So I could run Magnetic Hard Drives at full speed.