Okay first lets recap whats the difference between a bezier and a Nurbs curve. Not much a bezier is a special case of a nurbs curve where every span between a curve is as it happens a simple 1 span nurbs curve (so its in a sense a split up nurbs cure globbed together for convinient use).
Now nurbs curves are better in many ways than the corresponding bezier, for mathematical reasons also trings like rotoscoping are infinitely simpler on nurbs curve (in general because a nurbs curve contain 1/3 of the data off a bezier you could make your curve without a hitch), but it takes some time to get used to.
Okay then for sharp corners, Firstoff let me say that while in 2d a sharp corner is desireable a sharp corner is ALLMOST never what tou want in 3d reason for this is that no realworld corner is sharp enough to be 3d sharp (even a 1 degree 3d sharp angle is sharp enough for you to cut your beard on if you get my drift of how sharp that actualy is, even a sweords ede wouldnt be thei sharp).
yes. several ways, ill come back to this.
Not realy unless you want to use methods described below, but one should never draw directly ourt ep curves because doing so is a bit harder than you might think draw a cp and then snap the epcs after the fact (thisway you will get the tangential direction you want.)
As said use cv curves and dont be afraid to make many points.
Now for making things sharp. the default method its a bit quirky for those ebeginning on 3d because they cant absolutely positively se any benefit in this. Also the concept is a bit alien too.
Split it at the point where you want it to be sharp, you could even add a sharp corner smack in the middle of your curve! Now this migh seem lake a bad addwice but it isnt. Youll get a whole lot better in 3d once you understand that 1 object doesnet actualy need to be 1 surface or curcve to represent something that might clearly be (and soemthing that clearly in your mind is one object rarely in reality are one they are composed of sub parts just like 3d would have it). THis in a sense is doing it how illustratoor does it (not thet you can make a hotkey for this so it might be point and click if you wish)
method 2 use edit curves -> cv hardness or use weight tool (its a conviniency script so that you might manipulate the weights of points) and raidse the woight of a point. Incidentaly using this kind of featureset you could make curves into beziers and then just collapse their cvs. This could be scripted to snap to its corresponding ep and then making it sharp for a more illustratorlike way of doing things.
third methofd insert 2 additional ponts after the fact using insert knot.
notewrothy thing theres a curve editting tool that lets you specify points and tangent directions and sharpnesses whereever on the curve. Alough it wont magicaly make more info on the curve but other then that its a good tool to know exist. its a tbiit tricky to use so a additional advice id to select a ep first uless you want a arbitraty point moving. and then enter the tool
Ps. with more flexibility comes more responsibility too!