Is calculus 3 hard as compared to calculus 2?

calc 3 is more like calc 1 except you have to do integrate 3 times. As far as vector topics goes, its not too important if you know how to do dot/cross products. Though it is important to know how to do determinants.

As far as bad teachers goes, there really isn't much to do, try asking ta/tutoring center for help. So long you know how to plug and chug, you should pass the class.

It's all up to the individual, personally I found calc 3 to be much simpler than calc 2.

It is very similar to calc 1 just multivariate.  New concepts such as partial derivatives and vectors are extremely simple.  The only things that can get to be a headache are working with concepts such as line integrals, change of base, and just keeping things straight during calculations (multiple integrals and variables can lead to stupid mistakes pretty quickly.) In my opinion, the series and sequence topics in calc 2 were a little more difficult to grasp.  

Not sure how your university does math progression but if you have a "calc 4" (most likely linear algebra and differential equations) I find that to be even easier still.

Vectors are much simpler than they were probably explained to you I assume, because they aren't too complex and bad teaching has a propensity to make them seem like something completely bizarre and difficult to grasp.

Overall if you did well in Calc 2 I'd have to think you'd succeed in calc 3.  But that's just me.

I like Engineering Math by K.A Stroud. Concise and straight to the point. No filler, no pretty sounding rhetoric. Develops very good technical math skills. First book starts out with Arithmetic and holds your hand all the way to Ordinary Differential Equations. The second book contains more advanced material, no less clear and workable.

As for Vectors, the first book contains general info on Vectors among other things. The advanced book deals with Vector Analyses.

Nope, calc 2 should be the hardest

I believe Calc is the most! Do you know that discovered website that help me just passed my Calc 2? They are great help really!