Hello! I'm new! I'm bad at plants!
I "inherited" a cardboard box of 4 neglected but healthy plants. They all need some pretty aggressive TLC. With my black thumb, though, I'm afraid I'll turn them from overgrown but healthy plants... into pruned but dead plants.
My primary concern is the jade. It was my late great aunt's. I REALLY don't want to kill this thing.

(^ Front view. Jade cannot support its own weight. Not even close.)

(^ Side view. Poor thing is a mess.)

(^ The cardboard box where it's been living)
(1) It obviously needs some pruning.
(a) Is there a particular time of year/ type of weather that's best for pruning? Or worst for pruning? Is now (August) OK?
(b) How aggressively do I need to prune it?
(c) How do I baby it, to make sure it goes back to being happy and healthy, after I prune it?
(d) Side note: aesthetically, I don't mind it being all leggy and etiolated like this...
(2) How do I best go about starting new jades with whatever I prune? Do I just cut off those two ungainly trunks, let them callus over, and plop them into a pot of soil? I read something about starting a jade from a leaf; how does that work? Do you bury the leaf?
(3) It needs a bigger pot, too, I'd wager.
(a) How long after the trauma of pruning do I need to wait before repotting?
(b) I know you're supposed to repot in the spring, but are there seasons when you really shouldn't repot?
(c) This is probably about a 3" pot. What are my repotting options? A 5" pot but no bigger? A big shallow bowl-like pot?
(4) My apartment is not bright. What can I do to make this jade as happy as possible??
Thank you!! I'm sorry if ya'll have answered these questions a million times before... I just want to make sure I'm doing this as correctly as possible.