If you're gad positive, you're type 1. If you went on insulin straight away, you're not type 1.5
You're insulin doses seem pretty standard for a type 1. 1:10 is the starting point they use to try and work out your insulin to carb ratio. They don't seem particularly low doses to suggest any special insulin sensitivity. Your standard-ish doses could be being facilitated by the metformin, which is usually prescribed for insulin resistance and stops the liver giving out so much glucose, so if you stopped metformin your ratios might need to increase.
If you're cpeptide test was done just after diagnosis it's normal for a type 1 to honeymoon and still be producing insulin. The honeymoon can result in rather erratic pancreatic functioning, if you had eaten something particularly carby that might cause production of more insulin than normal. The cpeptide test is just a snap shot of what's being produced when they test - if you're taking a fairly standard type 1 total daily dose, you're not having lots of hypos, you've been in dka more than once it's unlikely you are currently producing "so much insulin" or indeed, any.