Okay, so I've completted Egg's assignment, brought Romaine her sample, deposited it in the terminal next to the ramp next to the transporter, and ... nothing.
I can't access her store. When I open her dialogue box, I can ask her four questions and then exit, but that's it; no store.
I'm a level 28, so I've really let it slide to this point, but I'm frustrated because she is the first step down the item upgrading path, and I haven't been able to access her at all (I've just been crafting new items from scratch).
Correct, you can only crarft new items not modify existing. ROmaine tells you to go see another guy who is off to the rooms left of where you deposit the sample and he gives youa quick crafting mission, after that crafting is open to you.