Newbie with Angular- need help configuring NG-Grid Custom Cell Editing

Newbie with Angular- need help configuring NG-Grid Custom Cell Editing

I have created a Plunker here: embed.plnkr.co/M1JHtX/preview or
http://plnkr.co/edit/mwedtS (obviously I'm new to Plnkr as well. :-) )
Hi, I am new to Angular and NG-GRID and while learning Angular is fun and
exciting to me I have been banging my head against these grid problems for
a few days now. I have three problems with this grid which are keeping me
from meeting my requirements.
In the middle column, there is a 40 character limit. When more than 40
characters are present on load the cell is marked as invalid by having a
red background, I was able to achieve this, however, when the user clicks
to edit it to limit the characters to under 40, and they don't, the error
message goes away. I need it to stay until they fix the problem. The
problem is, if they click to modify the cell, the formatting goes away and
the when they click out of the cell without modifying the red validation
is gone although there is still more than 40 characters. Also, how to make
the red background go away after user fixes issue.
A user should not be able to change the third column to VALID if the
Second column is blank. (Row 8 for example has a second column that is
blank and they should be able to modify the third column to Valid in this
case). I am not sure how to achieve this.
After focusing in and out of a cell the input box does not go away. How do
I get the input box to go away after the user leaves the cell?
I'm sure some of these errors are my grid option configurations and others
are probably really simple things I'm missing. Is there someone that can
mentor me so that I can tackle these issues. Our Company has decided to go
with Angular Grid for the project and I'm sure I need to know these basics
before moving on to other grids. Thank you kindly.