Nope, it's not. As a rule, not router/AP combo has bridging functionality. There are a couple of newer models that have firmware available that will enable it. No 802.11b AP/ROuter combos do to my knowledge. Firmware support, either mfg or third party just isn't paid much attention to with older wireless gear.
the linksys wap11 (older B) allows for bridging mode with nearly any linksys AP or router g stuff included. though i have had it work with a orinoco AP as well
if both units have bridging fuctionality in the config screens it should be possible
i have a 714 and i recall it being able to do nifty stuff like that
but i'm out of town so i cant get into it to check
Pretty much any dedicated AP will bridge. AP/router combo's, like the 714, especially older .11b ones, do not. That may very well be an exception but I doubt it. I imagine you wouldn't be asking here if it does since of course you wouldn't have had to. That assuming you had the sense to look around the admin gui to see if there is a page/tab for bridging. Check it out if you haven't but if you have and you don't see a bridging function page, then your out of luck.
Wider? If your running 192.168.X.X /24 where /24 is the subnet mask (255.255.255.0) then you have 254 available hosts. So I don't exactly know what your asking but there is nothing to do there. Yes, if you have your Parent router acting as a DHCP server then you'd disable any other DHCP servers on the network.