I've poured some where the thin edges have cracked and chipped off when walked on just right but covering it may help.
It will crack at an expansion joint if the joint expands and contracts but shouldn't be a major factor in a controlled temperature basement but who knows about the cold in Denver without taking measurements on the crack over a years time.
The floor levelor sets up very quickly (15 to 30 minutes) and is very viscous. It pours out thicker than pancake batter and doesn't necessarily self level on its own but requires a lot of hand floating to move it and level it. This isn't a skill most diyer's have. It is especially hard to level on a gently sloping surface. You can keep 2 or 3 people busy hand mixing that stuff in a bucket, pouring, and then troweling it in over a large area. Set some level chalk lines along the walls and have a long straight edge screed board for moving it around. Just like concrete you could pour it in sections but you have to mark the level on the section dividers.
Look for some type of elastic crack sealer on the cracks before covering it with leveling compound. Let us know how it come out when you get done.