Accents do make spelling reform difficult. For example, some of the people who grew up 5 miles from me (they were Cosham/Portsmouth, I was south Havant) pronounced both these "th"s as… I don't know the linguistic symbol, but something like a "v" or an "f".
What's your accent btw? In "standard" English, 'the' has a voiced consonant, whereas 'thing' is unvoiced.
EDIT: Sorry, I now see you already told about your regional accent.
Other than the specific location and the social category of "upper-middle-class", I don't know how to describe my accent. People at school thought I was posh, but I never saw myself that way.
Now I live in Berlin, so I might have started picking up a bit of a German accent (and perhaps an ESL accent if there is such a thing).