The security measures which are the primary subject of your question here (MAC filtering, non-standard IP addressing) basically equate to "security through obscurity". They are very weak against a dedicated attacker, and so should not be relied upon as the only security functions in your system.
That said, even security through obscurity has its place in a proper defense-in-depth approach. Anything you can do to make it harder for an attacker to compromise your system, while not having too much impact on the usability of the system, may be considered worthwhile.
My own home setup uses all of the things you've mentioned, and then some:
- MAC address filtering
- Non-standard network ID (doesn't even end in .0)
- Restricted (smaller than /24) subnet
- Reserved DHCP addresses for all registered devices
- WPA2 security on the Wi-Fi network
- 63-character random-generated PSK
- WPS disabled on the APs
Those last three items, plus reasonably strong physical security on the house, are the real things keeping unauthorized users off my network from the LAN side. As long as WPA2 remains fairly secure, nobody's going to be sniffing my traffic over the air let alone joining my network any time soon. If there ever comes a time that WPA2 is broken, and a suitable replacement is not available, I'm fairly comfortable that any wireless attacker (unless they are deliberately targeting me personally, or specific data residing on my network) is likely to move on to another victim before they bother trying to get into my network.
The only real down-side to these extra security measures is that it can be a bit of a hassle to get new devices onto the network - especially smartphones and tablets. For most people, adding a new device goes like this:
- Select Wi-Fi network, enter PSK from memory, hit "connect".
- (There is no step 2.)
For me, it goes something like this:
- Log in to the router's configuration page
- Figure out how to obtain the MAC address from the new device. Add it to the MAC address filter on the router. If there aren't any slots left in the filter (it seems Linksys routers are limited to 32), pick an idle device to remove from the filter to make room.
- Pick an IP address to assign to the device, add it to the DHCP reservations on the router. If no IPs are free, pick an idle IP to un-reserve and reassign.
- If the new device is a laptop or desktop, plug in thumb drive, copy and paste PSK to the new system, click connect. If it's a smartphone, tablet, or other limited-function device, load the text file with PSK on my laptop, enter the 63-character random PSK manually on the new device, and click connect. Repeat this step until successful.
So, adding a new device can be tricky - occasionally to a problematic degree. Fortunately, it's not something that happens often. Other than this, the added security measures really have no impact on the usability of the network for authorized users.
What do all of these extra measures actually buy you? Perhaps just a warm fuzzy feeling. Is it worth it? That's for you to decide.