Nita - I linked you to the overview in an attempt to help you understand 2 things. Growing well means that you have know where the "sweet spot" is. We can't provide some conditions that would be considered favorable and some that aren't, because it will always be the least favorable condition that limits growth and vitality. If everything is perfect but for 1 factor, that will be the troublemaker.
Fortunately, most houseplants do very well with only minor variances in their cultural wants. Other than cacti, if you can keep 90% of your plants in a soil that can be kept moist w/o a significant amount of perched water (soggy layer at the bottom - more about that in the next link), at about 70*, at a favorable light level, and using an appropriate fertilizer, your job becomes remarkably easy.
I'll try to answer your questions in order.
1) If you read the link below, you'll discover that it isn't so much what you "put in" your soil as it is the size and physical characteristics of what you use. Basically, you want to start with a very large fraction of coarse material - say 75-80%. It might be fine pine bark pieces or other inorganic particles. It doesn't matter, as long as it allows you to keep a favorable ratio water and air in the root zone. Too much water is primarily what you need to guard against if you want your plants to have the opportunity to grow as close as possible to their genetic potential. I have found that an extremely high % of problems folks come here seeking remediation for are able to be traced back to a poor soil as causal. Spoiled foliage, rotted roots and diseases, and insect infestations are most common, and soil choice is usually the underlying cause.
The link explains how water behaves in soils and offers a couple of recipes to build on. Understanding the concept has changed the way a large number of people approach growing in containers.
2) If the root system is still viable, the plant should recover, even though it will likely shed the leaves as a drought response. Remember, it can't effectively take up water w/o adequate air in the soil. Ideally, soil should only be about as damp as a well wrung sponge. If it was my plant, I would take it out of the pot and inspect the root system for dead roots. If you find slimy roots or a sour-smelling soil, you might need to do an emergency repot. If the roots seem ok, you can unpot the plant and set it on a mat of newspapers, paper bags, clean rags ..... for an hour or two. This will wick the excess water from the soil, which in turn allows more air to make its way into the root zone. I'll wait for a report from you before we go on to the next step.
3) It might be appropriate to return the plant to the container it was formerly in. Having the plant a little root bound in a container small enough that it doesn't remain soggy for extended periods is much better than the inverse of that condition.
4) Cuttings from a struggling/stressed plant are very low % bets. Getting a cutting to strike is a race. The plant needs to grow roots and make a vascular connection to the top of the plant before fungal problems rot the plumbing. The more stored energy the cutting has the faster it makes roots and the less likely it is that rot organisms will spoil the outcome of the race. You'd do better to try to bring the plant back to good health, and then take your cuttings, but you can try if you like. You'll need a very airy rooting medium and a warm, bright spot.
Kitty - I wouldn't use a fungicide on the soil if I were you. Your plant forms all sorts of relationships with other living organisms in your soil, some of which actually help the plant absorb water and nutrients. Any fungicide you select would probably be unselective, and likely to do more harm than good. The exception would be if you were having fungal issues with the foliage, in which case some sort of anti-fungal remedy might be more appropriate. Plus, what Tiffany said.
Al
Here is a link that might be useful: I'm about soils. Please click me then read me.
Q
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