My dojo has actually had problems because of this kind of thing. We can terrorise a room by sitting in corner reading a book, practically.
The first time we realised there was a problem was when we were in a bar one night and a bouncer came over and very calmly and politely said "You've not done anything lads, I have no problem with you but I have to ask you to leave because people are complaining about you."
Another night we were outside of a club and the bouncers were eyeballing us, giving us really suspicious looks and eventually one says "You four do something don't you?" We're were like "Yep" and he asks if he's going to get any trouble off us. We're like "no, mate" and he stands there just staring at us for a good half a minute and eventually he let us in.
We can walk into a bar and the place goes silent and everyone just stares at us. It's like a scene from a western when the gun slinger walks into the saloon.
It's become a running joke. The upside is that we never have any trouble with people, most guys wont even make eye contact with us.
It might help to stop wearing the Gi to the bar.
I've noticed a lot of martial artists have a certain self carriage. Its a combination of things that most people will not consciously register but instinct picks out. I've had it for a long time, expect the Aikido will only refine it more. Geeze I intimidate people as it is I can only imagine what it will be like when Ive trained for a good while. Most people, when I ask them, cant even begin to tell me what it is about me that is so scary.
Someone (martial artist) picked me out of a crowd once too and that was long before I took up Aikido.