What Switch series are you plannig to use at the center of your Star Topology? the HP 2530 isn't capable of acting as a Layer 3 device...
You need to decide if your Star Topology will have a Layer 3 device on its center (routing your VLAN SVI to your Primary Fortigate 100E Firewall through a Transit VLAN) on if a Layer 2 device is enough because you will uplink to the Fortigate 100E using a port which wil be tagged member of your various VLANs (no SVI).
Access Switches (1920) can be simply uplinked to Layer 2 or Layer 3 Star Topology center using uplink ports untagged on a VLAN dedicated for their management and tagged on any other VLAN you need to transport to them...edge ports (hosts) will be untagged members of one ot these VLANs.
Since the Fortigate 100E is multi-WAN capable I'm not going to discuss the upper part above the Fortigate Firewalls.