I would say that you need to figure out every step and then look at what else LMI will do. Im having them do my fretboard slotting and I may just buy an off the shelf bridge for the first one or 2 guitars I build. I also have a Martin reject neck for my second build, its 1 3/4 though, too small but what the hey. Saves lots of time. Have them thickness sand the top and back and sides also. It would cost you $30.00 for that anyway. Get a second set of bracewood for backup.
Depending on your materials/tools, you could do the rosette, or play it safe and have them do it. It would run about $100 for a Dremel setup, which works for me.
You may need a bending iron/ heat blanket for touch up, not sure if the sides are bent to glue up stage. Nothing wrong with putting 'parts' together for your first or second guitar. Like they say, it will take 5-10 to get a feel for it. Ive heard lots of good comments from thier kits, I always wonder if I should have started that way, but I got my 2 carpathian spruce tops for $30.00pp, so I couldnt argue with that.
Make the positive mold before you make the negative and see where the wood bends to!
And remember, the kit has plastic trim, you can get maple or whatnot for like $8.00 a topset.
Good luck.