Yes, your assumption of little over 1% looks good.
If we go by your statement 'With over 1200SP, I am earning about 0.5 SP interest per week.' then the rate comes out to be 0.042%.
If it is 0.042% per week then yearly rate comes down to around 2%. So your calculations look pretty close. Surely it is not very big return.
RE: 💰💲💸 No, just holding STEEM POWER won't make you a MILLIONAIRE so easily!💸💲💰