In a visual narrative, the way a character looks ("the looks of the guy playing him") is a big part of how we interpret him. Casting is never blind, and "shifty" (putting his hands under his arms nervously, the hint of a stammer) is often cinema/tv shorthand for "watch out for this guy." It's a little lazy, but cliches are cliches for a reason. Further, it wouldn't be "solely" based on that, because as some of us have noted, this show has a tendency to conflate characters and to transfer plots and personalities between them (Dale/Herschel). I think that since the name "Axel" has been applied to someone who seems nothing like the big Zen biker of the books, we can reasonably assume some other plot is being assigned to him - and there's a doozy that seems off the table right now, with a nearly-silent young blonde who has clearly been preserved for something. None of this theory is unreasonable.
I do take Mojochi's point, though, that it might be too much to play this card too soon after the Governor's creep-turn. At the same time, any relief the audience might have felt when the Governor didn't actually physically rape Maggie might be the fake-out. "Are ya relieved? Well, look what just happened over here, then, back at the homebase."