WNDR3700v2 router / bridge / client AP configuration help

I am interested in getting some assistance in pursuance of configuring my router to have the following functionality, can someone guide me?

By the way, I went on the Freenode IRC channel and over a one to two hour period not one person responded to my requests for assistance. In fact, I began to wonder if anyone was even seeing what I was putting into the channel. That channel is either broken or entirely useless. I did tryed a Linux channel (which worked fine) so it was not my connection or IRC client or that, it was something entirely channel specific.

Clients connect to the WLAN (WiFi) or LAN (Ethernet) should get an address via DHCP. In most cases I'd like the DHCP server to be on the Netgear router and to allow static DHCP assignment. However, there will be instances that I will be desirous of disabling the DHCP server on the router and letting DHCP requests go to the WWAN or WAN to be serviced also. Thus, an option to allow this would be very useful to me.

Most WWANs I'd connect to will ostensibly be on 2.4GHz (B/G/N), so that is really what is most important to me. However, if the ability for the WWAN to connect via 5GHz is possible, its a nice option but not a requirement for me.

I'd like for the WLAN to have a different SSID and authentication password than the WWAN if possible.

If OpenWRT can do this great, if not, can you advise if you are aware of any firmware that can? I realize this is an OpenWRT forum, but sometimes there is crossover with users of other firmwares I'd presume.

Some of the WWANs I'd connect to are hotel or coffee shop WiFis, so anyone with information about scripting my way past such captive portals would be interesting to me too. One Microtel Hotel I stayed in for example, had no an open WiFi but required a 4 digit password that changed weekly to be entered and tick box for accepting their usage policy to be agreed to, then it connected you for 24 hours.

Lastly, I have read and experimented quite a bit, so if there is something I should read and try I am open to that, but please understand that I likely have read it, tried it, or maybe never saw what you are recommending I review.

Thanks in advance to anyone that can assist or guide me in my endeavors.

WWAN - WiFi connection to the Internet from the Netgear to another WiFi network
WLAN - WiFi connection from a workstation to the Netgear router (can be via 5GHz if need be)
LAN - Ethernet connection from a workstation to the Netgear router
WAN (likely to not be used) - Ethernet connection to the Internet

Thanks again in advance!

openwrt would be perfect for your scenario. having said that, depending on your level of experience, you'll need to break down what your doing into simple achievable steps.

depending on your level of network / linux skills.....

disabling the DHCP server on the router and letting DHCP requests go to the WWAN or WAN to be serviced also

The above requirement is the only really tricky one....

That device is excellent for AP/ROUTING duties.... Bear in mind tho' to not load it down with additional services later on and it will perform very nicely.