First step - read the information I linked you to and make sure you ask about anything you don't understand. Are you going to be able to move the plant outdoors around Memorial Day? The best course is to allow the plant to retain its foliage until after it's repotted around Father's Day, and then do the pruning in July. You'll find answers to all the questions you asked at the links I offered, or you'll have all the info you need to easily figure them out. All my suggestions are offered in consideration of what it takes to work WITH the plant's natural growth habits. When the time is right is the time to take a more aggressive stance. For now, all you need to do is flush the soil & properly manage your watering/fertilizing. There is little effort involved in flushing the soil to ensure that an excessively high level of salts is not limiting your plant. Simply flush the soil thoroughly and repeatedly by pouring a volume of water equal to the volume of the container through the soil several (5-10) times - the more the better. After this treatment, you should fertilize with a half strength dose of a soluble fertilizer, preferably something in a 3:1:2 RATIO. Ask, if you don't understand the difference between the fertilizers ratio and its NPK %s. Of all the 3:1:2 ratio fertilizers I'm aware of, I prefer Foliage-Pro 9-3-6, for several reasons. If you don't want to order it online, Miracle-Gro 12-4-8 liquid (yellow jug) is readily available, inexpensive, and a reasonable substitute. Al

From what I've seen (never done it myself), you should be able to root larger cuttings (truncheons) of this plant as easily, or maybe more-so, as smaller cuttings. If there is significant new growth at the tips, you may have to prune back to firmer wood. A moisture tent and rooting hormone should improve your odds.

I had a similar situation to you - I tried to propagate a schefflera I received from a funeral - and foolishly took just a cutting off a petiole before I understand the biology of the plant enough to realize that it was a petiole and not a "branch". It looks like I might have taken mine a month or two after yours. It took a very long time to see much happening below, but given that the leaves weren't withering and looked healthy I hadn't given up -- and as of this morning I looked at the bottom of the plastic dixie cup I stuck it in to root and was surprised to finally see the tail ends of some roots poking around. So I believe the petiole CAN root, if you're lucky - I just have no idea what that means for the plant after it establishes a root base. I'm pretty sure the petiole/leaf structure at the top is not going to do much else, so my hope is that the roots eventually send up a new trunk/stem along side it. Time will tell. Hopefully by now you've determined if you have similar luck with your petioles.

Scheffs LOVE a medium that holds little or no perched water. They like a soil you can keep damp or moist, and don't revolt if the soil dries down to a rather dry state - at least not until the soil is almost completely dry. It's better to avoid drought stress, but given the choice between too dry or too wet, too dry will be much less limiting until the point where the plant starts to shed leaves ...... and it is rather reluctant to do that. The old Fafard mixes used to be much coarser than they are now since Sun Gro acquired Fafard. The nursery mix is about the best, and even that could use a large fraction of added perlite (3 parts nursery mix:1 part perlite). If you can find a source of pine bark in an appropriate size range, you can make your own and have no reason to ever look back. I started making my own soils about 25 years ago and haven't used a soil prepared by anyone else since. The difference is like night & day. What I use: Al