Sounds like the LYS shopgirl didn't bring her "A Game" to work that day! She failed to recognize your needs, and to establish a good rapport with you. Seems like there was a lot of her telling you what you think...and not enough time spent in discerning what you want and need.
I've never read a bad thing about Lion Brand Wool-ease. It's a fine yarn, and like mentioned by someone else, it's warm and washable.
As for sock yarn...why spend a boatload of cash for socks at the beginning? Jan is right, LYS yarns are usually of superior quality, but you have to measure the cost against what you really need. That's what I think.
For instance, I guess it could be said that I use expensive yarns for my own sweaters...but recently I bought some Lion Brand Super Thick (acrylic!) yarn at the grocery store for a log cabin blanket (for the floor) for my great-grandson due in June! It cost me under $50. And it's washable, soft and cushy. If I'd used Rowan BIG WOOL, the blanket would have cost $250. Now who needs a $250 baby blanket for the floor? :shrug:
And BIG WOOL is not washable whereas the Lion Brand yarn is totally washable!
So my less expensive choice of yarn is much better suited to this project!