Really depends on whats going to be used in production.
FCAW should be dragged for *everything* but vertical-up welds. I've been teaching this way for 8 years and while we have some fusion issues at the root/backing strip from time to time.. I have never seen a slag inclusion in a FCAW test weldment done with a drag.
Weaves (the allowence of) depend on any heat input regulation that may be in place. Weaves are fine in everything but the horizontal positions, but stringers tend to trap less slag.
The wire you are talking about will easily do 5/16 single pass fillets, prolly 3/8 would be a snap.
If the prep and backing weld are kosher, you should see absolutly no slag inclusions.