You'd really need an experienced, professional psychologist to answer your questions. I just thought I'd give you some of my own experiences, in case others recognise them at all!
Unless your 'voice' gets worse or starts instructing you to do harmful things, I'd guess it's your brain's way of helping you cope when life feels a bit confusing. Also, a vivid imagination is something to appreciate, really, and not all that weird.
I've got three types of inner voice.
One's a constant internal 'voice'. This one doesn't actually sound like a voice, it's mental chatter. Most people have this, and are surprised to learn that some don't!
With me, it spends a lot of time criticising. In therapy I learned how to 'listen' to what it's saying, and realised the criticism comes from childhood, when I was harshly punished for getting things wrong. There was a lot for a kid to remember, and I never knew what was 'wrong' before getting punished. So I developed a sort of mega-critic in my head, always telling me off, in hopes of getting a jump on my parent and avoiding the punishment.
Once I'd understood that it was trying to help, not deliberately undermining me, I started making friends with it. I called it Fucky Nell because it was always saying 'fucking hell!' 😂 My project has been ongoing for about 15 years now, and Nell is definitely easing up, even being kind sometimes.
Another type is much more like a disembodied voice, although this one doesn't sound like a real voice either. It pops up at times of great distress or emergency, and issues clear warnings or instructions. Your 'Be Normal' voice might be more like this one?
It is invariably right: in any case, I wouldn't ignore it. I have a theory (psychological/neurological) about where it comes from but that's not important. What is important is to know that many people have reported this happening when they've been in life-threatening situations, and it has saved lives.
The third type's an hallucination. I get them often, due to fatigue. The auditory ones are usually stuff like music or people talking in the background, but can be definite voices speaking clearly. Since I know that I hallucinate, I do a little checking routine when something unexpected happens, and only react if it's definitely real. They can make me jump, though!
I used to tell lies a lot, very much like your Halifax story. In the moment I believed them to be true. I got fed up with it; it was embarrassing if someone said "Oh, Garlic's been there / done that" when I haven't, and I didn't really know why I was doing it anyway. I stopped doing it. If I'm over-identifying with someone else's experience, I do a little checking routine before speaking ... I might still go ahead, though, if it's harmless!
You know, you might've seen a film set in Halifax or wherever, and have internalised your positive impression.
Your escapist fantasies are really nothing to worry about. It's actually a gift. Loads of people do it most of the time, and other people seek the experience through hypnotherapy or drugs. Mine are rarely that vivid any more, since starting antidepressants, but I still have a very good imagination and am grateful for it.