I probably just rambled too much, so I apologise!

You are not going to get rich from solo mining in high-sec. I would recommend you do some PI as well, you can modify your planets while you are out mining, and then go and pick your stuff up every few days. It may also help if you can move the goods yourself (i.e. with freighter) or find someone willing to buy all of those minerals at your location. As freighting services will cut into your profits as well (although only slightly). If you only mine scordite, get scordite processing to 4 so you can use the T2 Mining Crystals in your T2 Strip Miner. Are you using T2 Strip Miners? Because T2 Strip Miners are worse than T1 if you are not using the Mining Crystals (which you haven't trained for yet). Other than that, move up to Exhumer when you can and look into doing PI.

While the profits are low, you are also not risking much of your assets. If you stick to retrievers you can purchase a new one with only a few hours of mining. If you do PI as well that will net you another 200mil a month with minimal effort. You can continue on this path, training whatever else you want to do in the game until you get more time, with quite the nest egg built up. While solo mining in a Retriever I would not expect more than 10-15 mil per hour profit. But with 6-9 hours a week and with 200 mil per month in PI you can still bring in 400 - 600 mil a month. If you train Ice Harvesting, and find an Ice Belt you can make much more mining it than Ore. The Ice Belts don't last very long however, and there are far less Ice Belts than Ore Belts. Also you can train drone skills and Mining Drones to increase your yield.

And after Mining, Refining and PI comes probably using your own minerals to produce stuff to make even more money. Then a Trader to sell it in the most efficient way. If making money in Eve is you goal, the sky is the limit :D

The 5 Bill ISK I made from it (and making Fuel Blocks) this past month highly disagrees.

When you're talking about 30,000M3 worth of ore then no there is a very minor difference in price after refining. But once you get into fleets, start getting mining boosts, have higher skills, etc. the difference is pretty considerable. It might take you 45 minutes to fill 30,000M3 of ore but players who play multipule accounts, have boosts, T2 crystals, maxed skills can mine far greater volumes of ore, so refining becomes very important (I can mine something like 24,000M3 of ore every 2 minutes roughly for example).

I recommend getting enough to purchase a Mackinaw because it has 35,000m3 orehold. It is really aimed at ice mining but it is the best solo semi-afk miner out there.

If you enjoy mining, don't have a lot of time to play per week, then I would recommend mining missions. I chose agents based on whether their corp has level 4 R&D agents. Some are very quick, some take forever (such as the ones where you have to slow boat 40km to your rock). There are a mix of gas, ice and asteroid mining. By the time you do level 3 mining missions, I recommend T2 drones.

You get your own pocket of space to mine in, with special asteroids (you could use mining crystals on them, but I don't think they're worth it). Some missions have specific rats that appear. You can get normal belt rats for the system. If your mission spawns drones, I recommend salvaging the wrecks. Armor plates have gone up in price (the new capital sized rigs need about 5x more than large rigs, and armor tanked capitals are the standard).

No, it's not sellable, well you can on contract, but there won't be much demand.