Rosy barbs are quite peaceful, I can't see any problem with keeping them with gouramis. They may chase the cardinals a little, but they shouldn't nip at them and they definitely won't eat them. Gold (Trichogaster sp.) gouramis, are more territorial...hopefully yours are females and will stay peaceful
Pfft, most people at Petsmart really have no idea what goes with what, the employees around here all think of Malaysian trumpet snails as "parasitic" when most people with sand tanks, keep them on purpose. They are always really surprised when I ask for some!
Just like with cardinals, if I buy a dozen rummies I can always expect at least two to four, to disappear on me. They seem to be very sensitive to any drops in temp, also. But if you don't like how they look, that's nothing to worry about!
I can't really figure out what your aesthetic for choosing fish is, why don't you check out a fish book like this, and choose fish you find appealing:
http://www.amazon.com/Tropical-Freshwater-Aquarium-Compass-Guides/dp/0764130560
(This is a great book, I paid $12...full price...and have gotten years of use out of it)
You can always check Aqua Advisor or here, to see if they are compatible.
It actually was my LFS, not Petsmart, that said I couldn't have the blue tetras with the gouramis. They did fine, but I just needed some dithers for my Anya, so they got moved with her and are doing good. And my two are females, and very peaceful so far. That was also why I kept them over the trio (1 male, 2 females) of blues, the blues were far zippier and much more rambunctious, the golds are so much more laid back, especially the older, 4.5" one. She doesn't bother anyone, nor does the little 2" female as well
I def need more MTS, I got some from my moms bf but I forgot my assasin snails were in there at the time, so they killed the biggest 2 :/
And as of two days ago 6 fish died, but the 7 left are very healthy and happy and doing great!

And no illness, water quality was good, so just them I guess.
As for the rummys, they don't have enough bright color for me I guess
Basically here is what I like
-anything that is a bright shade of blue (blue platies, cardinals, neons)
-any really bright or shimmery fish (i.e. orange creamcicle sailfin mollies and rosy barbs)
-any fish that has leopard or similiar intricate patterns on fins (the gold gouramis fins are really pretty on the ends and long finned leopard danios)
-pretty much any longfinned fish that has bright colors or resembles goldfish (i.e. serpae tetras and rosy barbs)
-fish that have white tips (like serpae tetras, pristilla tetras, and my favorite, LF BN plecos
-pretty much any catfish
But then again there are exceptions to the rules..lol I def think I will buy that book, better then using liveaquaria all the time. Lol.
And yep, def use aqadvisor a lot! I'll play around with stocking, then post my plan to see if people think it's good. Thanks
