Looking good!!!
Delays seem to be the order of the day when it comes to some contractors.
I have a neighbor waiting for a long time to finish a simple structure. All he seems to get is one excuse after another.
As for suggestions: are those attic trusses? If so, great. If not, not a problem. Just lay some inexpensive ply on the floor and use this for storage. Put in a pull-down attic stair and instant storage space appears. Lots of nice space in there, but it won't take long to feel cramped when the toys arrive.