Ri0Rdian,
Yes, MSPs are indeed made from the minerals, in the proportions, you state. You can confirm this in the Mining tab. This also works to figure out the proportions of minerals you need for missiles.
I certainly agree that the game UI could provide information better!
That said, there are some ways we can keep track of our empire-wide mineral production and consumption right now. First off, don't worry about total production. What you want is a better sense of what minerals are at risk of running short, before they run out.
The Economics window, Empire Mining tab gives you total stockpiles and global stockpile change in the last construction cycle. Some tips:
1. Get a sense of what a "comfortable" value for the Stockpile of key minerals, including Duranium, Corundum, and Gallicite, are. If the values here or on your major manufacturing world(s) drop lower than you like, keep shipping mines to worlds that produce said minerals.
2. Try to keep the Change values mostly positive, except for the TN minerals you're heavily chewing up at the moment. You want to be generally growing mineral stockpiles over time, except during surge production periods, to keep up with your expanding empire production.
3. Compare the Total Stockpile values to the stockpiles on your major manufacturing worlds. This can clue you in that a government or civilian mine has minerals that aren't being carried away.
4. If you still have trouble, then consider turning a freighter into a ore dump. Stockpile a few thousands of critical minerals. If you run out, tap the reserve and use it to start solving the resource crunch.