The moment this picture showed up online my girlfriend said the exact same thing. It took less than 48 hours for this to turn out to be proven true.
UrsineApathy
I promise you that nobody will give you a hard time or look down their nose. Like another commenter mentioned, the only real difference is that you won't be able to be in a corral at the start line of the race without a number, otherwise you can just run the race route like normal.
Runners in general tend to be a super positive bunch of people in my experience since the entirety of it is based around achieving personal goals. Unless they're marathon qualifiers, road races are almost exclusively charity runs anyway.
To add to this, just make sure to add a long run day once a week before your rest day that's like 70-80% of your target race distance, so 7-8K, and that's basically a standard race training schedule. Work you way up to this distance at first of course so you don't hurt yourself, but you're definitely a lot farther on your training than you think you are.
I think this is the right answer. A combination of being drugged against your will with no comprehension of what's happening and then a big creature (That you probably associate in some way with that bad experience) chasing you down. Cats are going to do what they want. Just be a nice person to Gregory and keep feeding him, but don't force him to eat if he doesn't want to or accept pets if he doesn't want them. Let him make his own decisions and don't chase him around.
And if you're going to keep feeding him, invest in a bag of dry food. Tuna is okay every once and a while, but the salt and mercury isn't good for them to have as an everyday meal.