The MiktoTik switch/router CRS326-24G-2S+RM (
https://mikrotik.com/product/CRS326-24G-2SplusRM ) can use either
SwOS or RouterOS. With RouterOS installed, can it be configured to have more than 1 WAN port
for Load Balancing the WAN traffic?
This switch is good if you want routing inside your LAN between subnets [VLAN] BUT it is not very good if you want to do WAN to LAN Routing. So from a switching perspective - YES it can switch at wire speed but cannot route at wire speed.
If you want to route at wire speed on the switch YOU will need to look at other brands.
My suggestion is if your network is small ...i.e. less than 100 users ... then get a good router like the RB450Gx4 and combine it with the CRS326-24G-2S+RM switch and that will be an excellent combination.
You will need to identify your needs properly to be able to get the right gear.
Inter-vlan [sub-net] routeing is a very good idea when the SWITCH in question can effectively handle the load and the load all depends on many factors.
Yes the CRS326-24G-2SplusRM can have as many WAN connections as you may desire BUT the performance will be poor.