It will only count if already transferred to the U.S. entity prior to filing the I-526.

Technically, any lawful activity can qualify, and inventory can technically qualify as capital but in practice this type of case is very difficult because the salaries alone will cost millions.

All types of (federally legal) businesses qualify for EB-5, and an import-export business is fine.
A definition of qualifying EB-5 capital is provided below. You can “invest” inventory – i.e., your investment does not have to in cash, but you will have to show that you personally own the inventory and how you purchased it with your assets.
Congress has defined “capital” as “cash and all real, personal, or mixed tangible assets owned and controlled by the . . . investor, or held in trust for the benefit of the [investor] and to which the [investor] has unrestricted access.”[5] Also consistent with past definitions, the statute now provides that capital must be valued at fair market value in U.S. dollars, in accordance with Generally Accepted Accounting Principles or other standard accounting practice adopted by the U.S. Securities and Exchange Commission, at the time it is invested.[6]