All that a longblock is...is a motor built with heads, etc. Shortblock means it's a motor built without heads etc. A long block doesn't necessarily mean it's better than a shortblock. It just means that it's more *complete* than a shortblock.
Yes and no... yes if you have everything that you need to run the engine, like harnesses/wiring, transmission, clutch, accessories, etc. The longblock is just the engine. Most swap prices out there are for full "changeovers" that include pretty much everything that was tied to the engine.
What people don't realize is that nowadays, the price for a B series w/o tranny is going for pretty much the same price as a ZC w/o tranny from a company not a private party. If you can get your hands on a cheaper tranny off of thepartstrader or somewhere else, you can have your cake for much cheaper than you thought you would (and then eat it too, if you want).
not really..you still have to find an ECU for 100, a distro for at least 60, a tranny for 300, a cut harness for 150, axles/intermediate shafts for 150, and bam, just like that, you're at $1200, the price for a complete swap.