You could set up a mesh network using COTS wi-fi gear, and disregard amateur radio directly. Some larger conventions do this every year. You'd have to set up DNS and whatever websites you want running on the network as well. This isn't something you can load on a Raspberry Pi and have it up in 20 minutes (yet).
Ham radio will give you long range comms and text based communications no issue. It can do much more, but the equipment and software to do so is still in it's infancy, combined with limitations on data rate. Think 1980s computing tier data transfer rates of <300 Baud for the really long range stuff.
Yes and no, You can do some pretty cool stuff these days, Data modes like OLIVIA can transmit usable data while literally hiding in the noise floor, and even well honed operators will have trouble locating your signal. It seems to be a minority of hams that are playing with the current state-of-the-art, though. For high data rate stuff you're going to be limited to the Ghz bands and line-of-sight only though, not unlike a wifi router.
Given the nature of what we're dealing with, talking and sharing info anonymously is about the best we can do. Identifying yourself here is to paint a target on your back, who knows who is monitoring this site. I can't understate just how crazy it will become if they take out the net for even a short time, think every financial and logistics network suddenly grinding to a halt. There is the issue of operator training as well (Again, google what happened with the ARRL and puerto rico recently. They got asked to leave, and sent a total joke of a disaster support team. I suspect this is the 'quality' level of many hams out there)