biochemistry - Monosaccharides configurations (alpha beta, D L) identification

I am really finding it difficult to identify the correct configuration(s) of a given monosaccharide, in fact my friends and I have been trying to solve this, much to our annoyance.

In one of our classes, our teacher said, in cyclic form:

If $\ce{CH2OH}$ is below the ring its configuration is L, and if its above the ring its D.

If $\ce{C1}$'s $\ce{OH}$ is below the ring its alpha configuration and if its above its beta configuration .

My friends seem to agree with the above explanation, however my understanding is:

If all groups of $\ce{OH}$ and $\ce{-CH2OH}$ is reversed from D form, its L.
If $\ce{C1}$'s $\ce{OH}$ is on the same side of the ring as $\ce{-CH2OH}$ its beta else its alpha.

So I want to know if these assumptions are right:

1. 
   
   

   D and L in linear form:

   
   
   
   
   • If the last chiral carbon's OH (one before the last carbon) is on the right its D and if its on the left its L. so if you want to make for example L glucose from D, you should reverse ALL groups.
   
   
   
   


2. 
   

   D and L in cyclic form:

   
   
   
   
   • It's hard mainly but can be deduced by making linear form into cyclic and cyclic into linear and comparing them or reversing all carbon branches.
   
   
   
   
   


3. 
   

   Alpha and Beta in cyclic form:

   
   
   
   
   • If the carboxyl carbon's $\ce{OH}$ is on the same side of last ring carbons branch ($\ce{CH2OH}$ in glucose, $\ce{COO-}$ in glucoronate) it's neta, else it's alpha. So in D form, if $\ce{OH}$ is above it's beta else it is alpha. In L form, if $\ce{OH}$ is above its alpha else its beta.
   
   
   
   

Also when i see 3D linear form of Glucose it doesn't match with 2D at all: 2D view of this site isn't like what I find in books I can't find the match between 2D and 3D view neither.

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I'm still confused because of following examples:

1-Alpha-L-Glucose

2-Alpha-D-Glucose

3-Beta-D-Glucuronate

4-Beta-L-Iduronic Acid

these just don't match.

also Harper biochemistry image is this:

but lehningers is this: