Sounds like you've pretty well got a handle on this. While they are a far cry from ideal, For beginners, MG can be a real godsend. It can also fuck you really hard and not in a pleasant way. But you sound like you have the common sense to start out at half strength, and to wait until the soil nutes are pretty much used up. So far, you're way ahead of the curve. Good luck!!!
One other thing you want to be aware of is the chemical salt build up that occurs in soil when using chemical nutes. Research "Flushing". The salts accumulate in the soil, and eventually build up to toxic levels, so you need to flush them out periodically. This isn't a problem with organics, so at some point later on, you might want to look into that.