I hiked MT and WY south to Steamboat Sprgs CO as three LASH's over three summers '07 - '09 so some of my info is dated. I gather you plan to section hike as you did the AT. If so be aware that timing is hard to preplan and bailing early is difficult in some places. I would expect normal phones to be unreliable.

Looking at your list but including random thought

The official trail as of a few years ago was to start at one border and end at the other. There is an "official" map and there are a lot of official trails. However that same organization accepts all routes as official hikes. Most of the trail is open to horses and bikes. Older sections go through parks and Wilderness areas that don't allow bikes but newer (last 40 yrs) allow them and as such avoid some more scenic routes. Most thru hikers skip sections (loops) and take alternative routes where they can take shortcuts (Henry's Lake, Butte, long day hike in RMNP, San Juans). Likewise there were 'official' routes that ran cross country parallel to empty dirt roads 100-200 yards away. These are different hikes with different footwear issues. Depending on the time of year, snow and high water force or encourage one to take alternative routes particularly the San Juans in CO and parts of Glacier NP but also the Winds and the area south of Glacier. Fires from previous years as well as the current year may also limit your hike especially later in the year. Fires are rarely put out. Early in the year the FS, Glacier and Yellowstone work with hikers to enable thru hikes and alternatives where possible and post info in many back areas as closures occur. Later in the year they close whole NFs. There are alternative starts that have different issues. In the south water availability, remoteness, hiker numbers, shuttle availability, map reading skills, river water levels and scenic considerations will help determine which of three routes to take. FYI, water is much more available than it used to be. Spring of course has the best supply. Current info is usually available for the key sections.

As a LASHer I was not under a time constraint. Henry's Lake route is great(saw nobody)as are the San Juans(popular once the snow melts}. The Butte route is mixed with a lot of mining areas, some heavy ATV use, some beautiful high meadows, old mining camps, no other hikers and some newer sections. Part of it was guess work for me. The route includes two 20 mile dirt roads crossing a valley. The alternative is much shorter but included about 30 miles of highway. 90-95% of thru skip Butte and Henry's lake and sadly the same percent skip the San Juans due to snow.

Each section is very different and changes during different times of the year. Again, snow and water are issues but so are mosquitos and campsite availability in Y and G. FYI in late June I no real problems getting walk up permits or changing them. Risk in route finding and escape or bail routes are also issues. Bring a wide area map.

Resupply was not a problem with preplanning. Seems like 100 mile segments were the norm. Longer if you wanted to skip a hitch or mailed resupply. In some cases you may take an alternative route for better resupply. Could get a taxi to South Pass city and Glacier. Took a bus to Lima from the south and from Lima back north to an airport (had to call for special pickup) but I think a shuttle may be arranged. Also took the train across the southern part of Glacier. Hitched to Steamboat Spgs. Shuttle available there and also from Denver.

There are a lot of dirt roads but they are still scenic. These are the wide open spaces of the west with great mountain views interspersed with arid areas, river cliffs, high meadows, wild horses, antelope, moose filled creeks but also ATVs and motorcycles were they shouldn't be.

Please don't join the people who stare at their tiny map on the GPS or on the phone blindly following them especially those who can't use them. These are nice things but you need to have map skills and develop comfort being off trail or somewhat discombobulated. Be prepared and supplied to backtrack, go around, or even head south(north) knowing you will get somewhere eventually. Others disagree but the tiniest compass has always been all I need. It can be hard to use if you don't have a larger map to figure bearings to distant or even nearby peaks. Most trails in the north are not marked, some cross country routes have great cairns others have cairns going every direction.

The CDT route actually goes around the winds. Plan on taking the higher route even in snow. If you can swing it, a route over texas pass is awesome as is the Cirque of the Towers. Ice axe needed in June maybe later but not a steep route. The route in drainage south of Cirques drainage is dangerous until the snow melts but ever so wild. The Cirque will have crowds as will the CDT (low trail) as soon as the snow melts. Alternatives the northern winds can be good cross country work with med-low risk. The older maps (Ley maps) have great notes especially on scenic routes and water. This may have all transferred to Guts maps,idk.

It rarely rains in the winds. It rains a lot in CO. It cools off at night. In the north light raingear is fine that can double as an extra layer. Grizzlies may occur from Canada south to Lincoln.

Southern New Mexico might be best to hike in Spring due to water. Don't know the month. Be aware that the Gila river may be unpassable for a month. But sobos hike it every year. It has some elevation in the south so heat isn't terrible but you know avoid july aug. Be out of the mountains by rifle season (late sept?). Water caches(from others) is highly variable depending on time of year and thru hiker crowds. Have options. One route is on a well traveled road.

Gloves are good for sun protection. You may not use them but something lightweight is good if your burned or start to get red. Same for suntan lotion. Ears are also particularly vulnerable. Mosquito repellent is a must until fall in the mountains.

I averaged 15.5 mpd on my first AT including nearos but not zeros(I was 39). Less before Smokies. up to 25 in the middle states. I planned 20 mpd on the PCT and CDT. I bought and/or mailed food occasionally. You can adjust based on terrain. If you're going to hike road you may increase miles. Some gravel roads and cross country in open areas are what killed my feet. Plan less in Glacier due to many issues including reservations. Carry food in general however for extra day as resupply between scheduled places in almost impossible and certainly a pain. Trail angels are those people who give you hitch and never have before or randomly stop and offer water, soda, or beer.

Worst part. The nasty undrinkable water south of Rawlins when my feet were extremely unhappy. North of Steamboat to Wy border, I hated the views of the great wilderness areas to the east that I wasn't in. Instead it was a wide cattle/ sheep trail that had lots of atvs. Paved roads(2), gravel roads(2)Getting there and getting back. Best part Glacier through the Bob especially the red mountain early season alternative - bear, sheep, goats and everywhere else(avoids border crossing/easier shuttle. You might even run into someone you know (shout out to Hawk and Zaz). I love the Winds but really the high country. The CDT avoids all the great parts. Do at least an overnight to ?? and camp at the pass with a great glacier view off of the high trail. Likewise at least hike into and out of the Cirque (two high passes to add to your hike). Loved some of the dirt roads, high quiet country with unexpected small pleasures.

I used an original tarptent with no floor but carried an5 x 8 tarp as a floor. I would have preferred a zip off floor. The tarp doubled a few times as mid day break shade and shelter from short downpours. In mosquito season omg you need a place to hide. They are relentless all night long and when you stop. I am not an ultralight hiker.