This was asked to IK:
I would like to use SampleTank to save my midi files to wav loops that others can use.
"If you are using the loops for performance or creation of songs, that is certainly ok...
If you are not looking to sell or create them as a library to eventually sell, you are ok to use the loops for music making."
If you are unsure please contact IK yourself.
So,
1) they confirmed that we can use their samples in our own performances and songs
2) they strongly implied selling or planning to sell would be a problem
3) they kinda dodged your direct question about whether you can distribute for use by others if no sales take place (or maybe you could conclude that because they did not strictly prohibit it it is allowed?)
Thanks for asking them!