I am no expert on e-scouting but have done my fair share over the years (some successful & some not) and it is extremely helpful, specially if you have a fair amount of hunting experience with the game animals your scouting for. The more knowledge you already have about the habits of the specific game your hunting can really help focus in on specific areas.
It is very difficult to discern Elk trails vs deer vs. free range cattle and so on in Google earth. Given a known Elk game reserve or something like that close by you can assume the trails are primarily Elk. Elk will often travel in single file even in large herds. Most often the trails you see on google earth are pounded in over years of continuous use by game animals. What these pounded trails can tell you on google earth is corridors of travel. The key is to put your boots on the ground and find out where those well pounded trails lead (bedding, water, food sources, mineral sources, dens and so on). E-scouting can only do so much in the way of giving you "clues" as to being a viable area to check out. If your primary hunt style is ambush and you hunt a time of year that supports that style of hunting the well pounded game trails can be a place to start. I must stress that boots on the ground and game cameras are your best friend. Trails can be used heavily for 1 or 2 months (look like highways on google earth) then go dormant for the rest of the year. Take for instance mineral sources. Elk will hit them with absolute clock work and regularity early in the year as they come off winter and then not even bother with them for the entirety of the rest of the year. Food sources are similar. As the food goes away the Elk will move on. Other things that can change behavior aside from time of year is pressure (hunt pressure, vehicles and people in particular). Many reasons hunters try and find an edge by getting out past the crowds or finding an area that is difficult to get into is to alleviate the hunt pressure scenario from the many scenarios that play into why animals are in a certain area at a certain time of year.
As far as designated foot trails, ATV, Horseback or other it's always nice to pair your e-scouting with an application like Basemap or OnX maps. All that hard work has been done for you and set into overlays that can be EXTREMELY helpful in determining access and egress to a hunting area.
Hopefully this helps some and doesn't muddy the waters.