You will only get the top inch of coolant with a wet vac so the answer is no. Radiators are a series of tubes and fins to increase surface area and subsequently aid in heat transfer. No way an off the shelf wet vac is going to help you here. As others suggest the radiator drain plug is one of the easiest to access.
Yes, the engine block has a drain plug on the rear, right side. The drain plug has a nipple that accepts a rubber hose. So you don't remove it, just loosen.
You don't have a clue how a radiator and cooling system works, do you... that's OK, we all have to learn how things work... Short answer, NO. :nothappy:
Now: Study this, consider that a vacuum hose will only reach maybe, maybe, the top inch or two of your radiator, and then try to imagine how it would be able to suck out all the liquid from the entire system and the engine block...
I guess a super-powerful vacuum could do it, if you opened up the lowest drain plug to allow air pressure to help void the entire system... but if you have to do that anyhow... you might as well drain it from the bottom like you're supposed to.
And now... Back to flights of imagination, like Transformer movies... D