Oh, I wasn't meaning that to be a response to your thoughts. I just saw the last comment that mentioned missiles and bombs but didn't seem to remember it had guns as well. I wanted to post up that picture back when the first wave of cycle critics questioned Batman even having guns.
Looking back on what you're saying I would have to agree to an extent. The barrels are probably long just for looks. Which may show a small lapse in awareness on Nolan's part as guns and comic book Batman is a touchy subject. But the possibility exists that the specific armament is mentioned in the script and maybe a certain calibre demands a certain size barrel. I have no idea what barrel length has to do with calibre. Never fired a gun in my life. My shallow understanding of guns is the longer the barrel the greater the accuracy. If Nolan wants to get into actually mentioning the armament as such and such a calibre I suppose it would be his want to make sure the barrel is at least in the neighborhood of what would be necessary.
Being a motorcycle there are limited places to put guns. Maybe between where conventional handlebars would have been? If they were mounted on the rear facing forward or to the sides of the tank I think they would have been more of a hazard to the driver. (shrug)
As far as effecting the driving I dont think it would. At least not average driving. It could make the bike marginally less agile. If he were to get a foot and a half away from an object before deciding to turn that would be a problem. If Batman wants to barrel through walls with this thing it would probably mess up the guns, but if we're really going to make that point then we should say it would screw up the whole front end as well and he wouldn't be able to control the bike throughout such a collision.
I don't think he'll be crashing through cement walls with this thing though. Maybe reduce something to rubble and ride over it but more likely he'll be jumping over the obstacles with this.
I do understand your point though. And for me I just think they're a tiny bit too long, looks-wise. They don't seem to balance out with the rest of the bike. Like they demand just a bit too much attention among what I otherwise feel is a really strong design.