While this is possible per the Ruckus spec sheet, my personal recommendation is to not rely on this density. I would feel a lot more comfortable if you had two AP's for 230 users, especially when the max internet bandwidth is a healthy 200mbit.
So far, setting up 2.4 and 5GHz with open (no encryption) is an excellent first step. Also, refer to these Ruckus guides:
Namely, I would recommend setting ofdm-only and likely bss-minrate to a higher value to force everyone to use a higher bitrate. OF course this comes at the cost of coverage range being shrunk, but remember, slow bitrate talkers are using valuable airtime that takes time away from nearby clients capable of talking faster.
I would probably stick with default channel widths (20MHz on 2.4, 40MHz on 5) since you have a single AP and running out of channels is not a concern. This would maximize everyone's bandwidth connected to the AP.
If you already have a DHCP server on your network (e.g. as a part of the router), I think it's perfectly fine to let it handle the leases.
For 230 users, I think you can get away with a single subnet. Once you get above 500 users, I'd start getting concerned about too much broadcast/multicast traffic causing performance degradation.
I'm not sure what kind of router you have, but be aware that sometimes cheap consumer routers really crap out doing NAT before 200 users -- I've even seen some where handling 20+ users is a challenge.
If you find that happening, you might have better luck having the Ruckus AP serve a local subnet with its own NAT and having essentially a double-NAT on your network. Since you don't need any port forwarding, this could work as well.
Perhaps I'll set up a subnet for this case. The router is a Zhone 2426 ONT http://www.zhone.com/products/ZNID-GE-24xx/ and I have to stick with it, since the internet comes directly from a fiber optic link. I've seen them handling 50+ users but this scenario is unknown, so if the Ruckus can handle the work without problems better use it.
Thanks a lot again John, I will apply some changes and test it before showtime, which is on the 30th.