Pang Nam Fui 
The white latex a cut stem releases is a skin question rather than a poison question, and I handle it the same way every time. This guide covers what the sap does at the cut, why the glove goes on before the blade, and where the severed piece goes next.
Pouring water through a pot is easy, and doing it before I know what the crust is only wastes the run. This guide confirms salt injury under the crust first, sets how much water the corrective flush takes, and names the new leaf I wait for before feeding again.
I lost my first Aloe vera to a watering can, not to a cold window. This guide sets out the light band, the dry-down interval, the cold floor and the gritty mix ratio I now use indoors, plus the check I run first when something looks wrong.
A firm rosette tells you nothing about what is under the mix. Here is the rescue I run on an Aloe vera whose root zone has failed: unpot it, read the roots, cut back to firm tissue, dry the cut face until it is dull, and replant dry.
A date on a chart cannot know how fast your pot dries. I water my Aloe vera by what the mix tells me: probe to depth, soak until it runs from the base, empty the saucer, then wait for that same dryness to come back before I go again.
Two very different faults make an Aloe vera rosette go slack, and watering the wrong one finishes it. I press one leaf against a firm one first: leathery means thirst, soft and mushy means the roots are gone. Here is the order I work in after that.
A rosette that lies open over the rim is telling you about light, not about support. I check the crown first, then read the leaf scars on the bare stem, and only then decide whether to move the plant brighter or start it again from the top.
Mealybugs and scale hide in the same place on an Aloe vera: the tight joins where one leaf meets the next. I wipe them out with an alcohol swab, then lift the plant out of its pot to check the root zone, and I keep repeating the round until nothing new shows.
Bagged succulent soil is a starting point, not an answer. I raise the mineral share with coarse pumice until the pot runs through and dries out fast, and I check the change by weight two days after a soak rather than by reading the bag.
A pup with roots of its own is a plant; a pup without them is a cutting. Before I separate anything I check underneath, and after potting I keep the medium dry and read the leaves for the first three months rather than watering on habit.