That is called zinc rot, seen it many times.
The copper plating has been compromised exposing the zinc core
which starts to rot when exposed to air. Might as well get rid of it
as it will only get worse with time.

That “dot” is a minor plating bubble.
That line is just a scratch which is considered damage.

Welcome to the forum

No problem with joining the discussion as long as you start your own thread with
a clear photo of both sides and explain what you think is an error.

Agree, the rim is just damage from a hit. The beads are from another coin being pressed into it.
No way for that to happen when the coin was struck.

Have seen a few of these lately.
It has been attacked by acid which has eaten away the surface
and rims accounting for the lighter weight.
You will probably find the diameter is slightly smaller also.

Not an error in any way, PMD. There is no way for that to happen when the nickel was struck.
The obverse has been ground off and the reverse is corroded.

Suggest posting pictures first before sending out.

If this is one of the “error” coins you were wanting to send to get graded, then don’t.
It is not an error, it is damage from being attacked with acid. Value 1 cent.
Suggest you post some of your other errors before you try sending them out.

What do. I think?
I think it is a badly corroded dime worth 10 cents.
What you see is the nickel outer layer eaten away exposing the copper inner layer.
It would be classed as a damaged dime.

Coin is pretty worn and missing a lot of detail but I am saying it is Obv.3

Welcome to the forum
The reeds have just be worn off of the one quarter after it left the mint.
It is considered damage and adds no value.

Welcome to the forum Sorry but that is not a die crack, it is a scratch which is considered damage. The raised part you see is from the displacement of the scratched metal. Your Loonie is worth 1 dollar. Also there are no specific errors for a 2007 Loonie. Any error can occur on any denomination and...

It has been coated after it left the mint, probably with nickel.
This was sometimes done to use in jewellery or even done in
High School,experiments.

Welcome to the forum

First, the correct terminology is a Doubled Die.
Also it helps to include a complete photo of both sides.
Yes that is a Doubled Die but does not add a great deal of value
and certainly not worth grading unless the coin is a high MS grade.

It is probably a broken post which is common on D and P mint marks
but need much clearer photos to say for sure. We need to be able
to clearly see the details.