I was a network engineer for many years, am a security architect, and am now a CISSP.
Unfortunately I have to be "that guy".
There are two major problems with what you provided.
An attacker cannot get onto your network easily unless you purposely set up open Wi-Fi where no key is necessary to get onto your network from outside your building. No need to worry about a hidden folder if an attacker couldn't get on your network in the first place. Do enable firewalls on your workstations to provide an extra layer of security such that even if your network is compromised an attacker can't access your workstations.
Changing your subnet address is pointless. The IP address of your router will be the same IP address as the subnet's gateway. If an attacker's device is already on your network, the IP address of your router will already be known because through the DHCP process the attacker's workstation will be provided the subnet's gateway. Scripting can easily look up the gateway address on the attacker's workstation and attack that address. Do set up a guest wireless network for visitors. Make sure it too requires a key so that it is not open. A guest wireless network will not allow access to the IP address of the router (among other things) so you don't have to worry about a guest hacking at your router.
I was a network engineer for many years, am a security architect, and am now a CISSP.
Unfortunately I have to be "that guy".
There are two major problems with what you provided.
An attacker cannot get onto your network easily unless you purposely set up open Wi-Fi where no key is necessary to get onto your network from outside your building. No need to worry about a hidden folder if an attacker couldn't get on your network in the first place. Do enable firewalls on your workstations to provide an extra layer of security such that even if your network is compromised an attacker can't access your workstations.
Changing your subnet address is pointless. The IP address of your router will be the same IP address as the subnet's gateway. If an attacker's device is already on your network, the IP address of your router will already be known because through the DHCP process the attacker's workstation will be provided the subnet's gateway. Scripting can easily look up the gateway address on the attacker's workstation and attack that address. Do set up a guest wireless network for visitors. Make sure it too requires a key so that it is not open. A guest wireless network will not allow access to the IP address of the router (among other things) so you don't have to worry about a guest hacking at your router.
You have the experience. No argument
What I was attempting (and probably poorly) was to NOT use the default settings a Routet comes out of the box with
You can scan network ID’s that are all defaulted to what it was sent from the factory with. That seems an open invitation to being exploited
Yes, you should change the username and password for administrative access.
It has been a while since I set up a new wireless router or wireless access point, but I highly doubt any of them have open Wi-Fi set up by default.