I'm on tropicbreezent's side - "a little and often". Fertilizer for plants is like vitamin/mineral supplements for humans - overdoing the amount doesn't necessarily mean the plant tissues or body organs can either absorb as much as is offered, or successfully deal with an overdose. I grow a few special plants that need special potting mixes that are mostly gravel and bark - they drain very quickly and it would be almost impossible to overfeed a plant, but I still wouldn't increase the dose of fertilizer I use. Other pre-mixed potting soils often have a lot of organic material/ premixed slow-release fertilizer/wetting agents that are intended to help the plant survive between waterings/feeds. By piling on the fertilizer you can be really adding to the burden by the fact that those soils will absorb and hold the water for longer periods, and if heavy in nutrients like nitrogen, can burn tender roots. Salts build-ups occur, the organic material starts breaking down quicker and shrinks and then the plant's not getting proper air exchange to the roots. So, don't "supersize" your plant feed, let then have a "lean meal" sometimes.

I sort of, kind of did the garden journal. I put my pictures on a webhosting service with a nice description and the date (either exact or month and year) and now I can go back at any time and see what was growing in my yard and garden during those years. I also ordered "booklets" for about $17 which had as many or as few pictures in them as I wanted. Just another idea for ya.

I’ve had that happen, just cut the brown parts off & put the plant outside for a while, out of direct sun. It will probably grow new shoots off the cut stems, mine did.

Normal potting mix for a succulent generally retains too much moisture, and 50% coarse sand helps but probably does not tip the balance. If you do not want to hassle with creating your own mix from scratch, I would change the soil to 50% commercial "cactus mix" and 50% perlite. I prefer pumice to perlite since it is heavier and does not float. Since you have your own greenhouse, I am wondering do you have a lot of succulents, and are most of those in the same soil and thriving? Is there any chance the greenhouse becomes extremely humid or hot?