1) The battery shunt will be located immediately after battery+ terminal.
2) You will connect the two yellow wires together to EXT IO4- and connect the EXT IO4+ to battery+ through a 470ohm resistor.
3) You can install as many monitors as you want but it will be redundant.
I do not see a PV shunt as that will provide you with much more info than just having the battery shunt.
If you decide to use the PV shunt it will need to be installed in series with the battery shunt (as shown in the SBMS0 manual) and then you can connect the two MPPT's to that shunt so that SBMS0 can show the PV charge current but also be able to calculate Load current as the difference between the PV current and battery current.
You can even connect the Orion TR smart to PV shunt but I guess that will probably almost never be used so not that relevant.
That will need to be connected to say EXT IO5- (set as type 1) on the H pin of that remote port the L will remain non connected while the EXT IO5+ will be connected through a 1kOhm resistor to vehicle ignition so that way both the engine will need to be running and the SBMS0 to allow charging and if you want also add a small switch in series so that you can enable charging from alternator only if you need that as it is at least 20x more expensive than solar charging.
On point 1) I see you have a 100/30 and a 100/20 and for the 100/30 the remote cable will work by default but for the 100/20 you will need to configure that in the unit using the Victon software.
Battery seems extremely oversized for the amount of solar available. For a 10kWh battery I will expect about 2000W of solar PV