Hello Everyone,
I guess this topic has come up many times but I really need some help and have photos so you all can look a them and tell me, what grade you would give them?
When I pick out MNH stamps to auction off, I only pick the ones with absolutely NO flaws, no marks no dings or anything.
With that said, can any of the below (photos) be considered MNH? And if so, how would I describe the backsides?
Below each photo, I have pointed out what I see wrong with the backside. Please note, the front sides are MINT, totally clean... I thank each and everyone who can help me out.

(1) Notice the bottom center, this stamp is not bent, but if you hold it in a certain angle you can see it looks slightly bent. Is this not a MNH? Or is it MNH with slight flaw, or fine or very fine with exceptions?

(2) Notice the slight round mark? The gum is on the whole backside, just slight mark. How would you grade this?

(3) left corner, it's bent, but full gum, MNH, what would the description be, or just as I wrote it "left corner bent" or would this not be considered MNH any more?

(4) MNH, OG, however you can see it looks like this stamp has very small speckles of black.

(5) You can see a small black dot on the backside. I just need to know how exactly to write up descriptions or how to use the VF, Fine, and what other terms are there used in grading stamps so I can auction them off with the correct wording.
Thank you all sooooo much!
SueStamps