A: I would not recommend that for this particular product.
A: The box it comes in is 42.5" x 7" x 6" so the unit is a bit smaller than that un-assembled.
A: Yes you should be able to use only the lower tier.
A: No the top tier is not adjustable.
A: No unfortunately it does not.
A: Hi slick. Yes. The arms and legs fold down, and the top and bottom can be separated for shorter storage, too.
A: Hi. The retail box is 5 x 7" and 42" long, but know nothing ever goes into the box how it comes out! So estimate a little more room unless you're very good at compact packing.