Have someone help you. Whenever i try to do it by myself, i usually prop it up by placing rocks around the rootball to keep them stable. And to keep them standing up put rocks around the base of the plant, or put a stick in the dirt and use string to "tie" it all together.

Very healthy looking! Looks like a bit of sunburn but that will not hurt at this point. Remove the string you have tied to the stick. They do like a bit more room...2-3 ft apart, 4 is best. And a much stronger stake or cage. They may easily grow 6-8 ft. Driving in a stronger stake will damage the root system now. Might try a teepee system by giving support from further out from the roots. Or a circling wire cage out of cattle fencing or similar to your region. (something in a roll that is strong and easily cut with wire cutters) Use something more flexible to tie them to your stakes. A cage will be a support itself. Another option would to just let them lay down gently and sprawl out right on the mulch if they have the room. They look low to the ground enough to accept that it seems...

I use many 5-gallon buckets to grow pretty much anything in - tomatoes, cucumbers, peppers and squash - the squash plants get HUGE. I think mine do so well because I created DIY self-watering buckets (see: Global Buckets). Once the roots are done filling the potting mix, they migrate through the holes I've punched at the bottom of the upper bucket and tap straight into the water reservoir of the lower bucket - sort of a quasi hydroponic scenario. I have had outstanding results from pretty much anything planted in buckets - the failures I pretty much attribute to selecting incorrect varieties for my local growing conditions (i.e. growing tomatoes better suited for cooler locations). Because of our arid climate, pests and disease are rarely huge issues. I will say I did not have great luck growing tomatoes or squash in 5-gallon buckets before turning them into self-watering vessels - peppers and cucumbers did okay. I just couldn't keep up with the watering, which was easily a twice a day affair, and the plants suffered as a result. A healthy full-grown tomato plant in full production can drink 2 gallons of water per day. My container garden is in full year-round sun on the south side of my house and in very close proximity (within 10' of the house), so mid-day mid-summer temperatures can easily reach 110 degrees. Nighttime temperatures almost always fall below 65, so the plants see wide ranges of temperatures almost every day. Keeping them properly watered by hand is futile by mid-June. I love planting in plastic whiskey barrels because they are large enough for even the biggest tomato plants, they look nice and hold moisture longer. Set up a simple drip system on a timer and the water issue is non-existent. They work great for a varied herb garden, multiple pepper plants, tons of lettuce, two tomato plants, large squash plants, you name it. Plastic whiskey barrels are less than $20 at HD. I think I've amassed 19 now, though 4 are permanently designated for extra dwarf fruit trees that are thriving. I change up the other 15 each season for whatever I decide to plant. I think they hold about 20 gallons of growing medium, so that is plenty for most plants for one season. Just remember to feed them regularly, as nutrients are quickly utilized by the plant or washed out the drainage holes by watering. I stick to a schedule of fertilizing each week or two and the plants do well.

I also agree with Gabby that your plants look good, at least from what I can see in photos. I can see couple of dry leaves in pic 1, which seems to me normal. Another leaf in same pic seems to be broken, with broken edge just dried up. If spraying with anything, it is best to do out of sunlight. Some ingredients may burn leaves in sunlight, even if not otherwise harmful to plant. Soil does look very 'dense', it could be too water retaining. If it contains too much peat, it may have become hydrophobic and it actually repels water. If to retaining, it may be staying too wet for too long, and roots may be suffering. Do as Gabby suggested - mix in lots of sifted perite. And do not worry about nutrients...succulents grow in very lean substartes in their habitat. Definitely do not use 'rich' soil thinking it may provide nutrients. If really concerned, it is much better to fertilize, lightly, with balanced fertilizer. I don't, and grow mine in gravely mix, made of grit, perlite and little turface. I have few small pots with bit of soil in the mix, but there is likely only about 10% of soil - added because I was running out of mix I usually use :) Whe repotting, get rid of old soil from the root ball. Trim off any damaged roots. The do not need to be drying if they have roots; if you have to do lots of root pruning, maybe an hour or two are enough to callus those cuts. If you need to wash off the old soil, letting plant air-dry for few hours should be enough (set it on something absorbent to help). If pruning off branches, the cuts should callus. Few hours or overnight is usually enough. But jade can live without water for a long time (weeks, even months) - they may shrivell, but still live. So do not worry much about how long. Cuttings, without roots, should be stuck into fast draining mix and do not water for a while. No roots - no water...they should start growing roots quite readily, and that is time to start watering.