[quote="RangerZ, post:34, topic:966, full:true"]While I believe that for this audience the Modem is still the primary device, Alberto does not agree, but he is on another continent.[/quote]Actually I was not disagreeing. I'm just stating how it is here on the other side, here DSL modems were dumb PC peripherals, not standalone devices. These things have pretty much all been replaced by modem/gateway devices long ago (mostly to get rid of the PC dependency). Older stuff lacks wifi, but is still acting like a gateway, so the instructions given in the original QSG are not working in the most common situation in EU.
I also said that if you want a true LEDE gateway setup you need to find a way to have a modem that supports the upstream protocol used by your ISP and that supports bridging so your downstream LEDE device can be the gateway and control the modem for DSL (or not control the modem for Cable).
[quote]All but Verizon offer some type of BYOD program which can still get one a Modem. This site summarizes authorized devices by carrier in the US. I expect the trend to lean towards Gateway (Modem Rotuers).[/quote]These are modem/gateways/wifi/whatever using DOCSIS protocol which is an industry standard, AFAIK there are no limitations other than technical (some modems like more some type of lines or dislike more some type of interferences, some are just cheap garbage, DOCSIS has different revisions and older devices don't support them all, and so on). Just google "docsis modem" and you'll find many such devices.
That site you posted states that they gathered feedback from people and ISPs to give you a list of products that will work well, they don't say that other devices using same DOCSIS protocol will not work because there is a whitelist or something.
For example, Comcast Xfinity requires a modem supporting DOCSIS 3.0, according to Comcast, (not just the one in that site).
They give a list of "recommended devices", they call "approved" but it's a recommendation http://mynewmodem.comcast.net/
"To ensure that your modem can take advantage of all that XFINITY Internet has to offer and avoid any service interruptions, you will need to replace your current modem with a DOCSIS 3.0 modem."
By googling it seems many DOCSIS modem/gateways still support bridge mode so it should be possible to get them covered with some instructions to get the ISP device to switch to bridge mode, to still give best effect.
But again, I don't know much about US networking and ISPs, and I cannot really check, this will have to be done by someone else on that side.
[quote]my playground version. [/quote]I like that. Good job. 
The "Understand Your Current Hardware, Firmware And LAN IP" might need better descriptions (also maybe screenshots of some devices) for the WAN and LAN ports.
The "Replace Your Existing Hardware With Your New LEDE Router" will need some change to work with people on a DSL (so that is using gateway device from ISP) as that part will work like that only for people on Cable (that is using a "cable modem" without gateway functions).
Also the "repeater bridge" and "travel router" could be joined as "wifi client device" because they are both basically using one of their radios to connect to a wifi network and will probably also want to generate another wifi for sharing the connection.
[quote]At this point I do not think the Repeater Bridge and Cellular methods (post 23) are easily accomplished. [/quote]I think repeater should be relatively easy, connecting to a wifi as a client isn't that hard with GUI (never tried with command line), see here RE450 as a repeater
But it is probably better to having just a link to a dedicated paragraph dealing with that in the "configure wifi in LEDE" page as any device can be set for that, not just those sold as repeaters.
Cellular should just link to other documentation or tell to go look in the device's own page (for devices that have an integrated cellular modem, as that is not core functionality.
EDIT: are we sure that there isn't also (many) people in the US that are not using Cable internet but some DSL variant? Because by googling I get tons of ISPs in the US that are not Cable providers (say AT&T) that offer DSL, not DOCSIS stuff.