Most likely the leaves will die if you try to grow them from cuttings. Anything is possible, but not likely. If the aquarium is set up for plants ( light, substrate and nutrients) the leaves will grow back quickly. Usually you just split the roots or rhizome and replant them to start new plants. Amazon Swords are heavy root feeders so a good "seasoned" substrate with some fert spikes is good. Also, if you aren't using Florite as a gravel you will need to add some iron rich ferts or laterite to the gravel.

No. If the plant has high available phosphorus, you will induce flowering. On the flowering stalk are nodes where new amazon sword leaves start to bud. Sometimes a stalk will branch into to. You can get 5-8 plants from this alone. I used to put chunks of pond fertilizer tabs with high P in the substrate to do this. I have since stopped after I got too many swords and felt bad discarding all the new plants. In any case, once you get a stalk, let the small buds mature to a decent size--you will know when they start throwing down roots.