RE: Can I not import JEs with multiple TRNS lines? 

You can't import any transactions with multiple TRNS lines.

In an IIF file, each transaction has one TRNS line, followed by one or more SPL lines, and one ENDTRNS line.

The minimum transactions will be:

TRNS

SPL

ENDTRNS

Yours will be something more like:

TRNS

SPL

SPL

SPL

SPL

SPL

ENDTRNS

Also, each transaction must balance, meaning the sum of the amounts must be zero (debits = credits).  In your example, all the rows are positive (debits).