I have to admit that I am finding it hard to attach values to Andrews. If you ask Blackburn fans who have watched him they are pretty split, with some saying he is a decent, fairly average squad player but wouldn't start if there was a choice and the others just think he is shite. On a good day he looks a decent player but on a bad one he is a liability. I'll try to address your concerns one by one to see if it will help.
Attack/Defence ratio:
He is really a box-to-box player who has, due to injuries(to other players e.g. Grella), been asked to play in a more defensive role. At MK Dons he played like a poor man's Lampard. High up the pitch is where he does his best work IMO. He can play dangerous through balls and is a goal threat. Defensively he is not very good as he is not a good tackler nor does he have the knowledge or discipline to play like a DM. I would tend to go for 70/71 for Attack but agree with 67/68 Def.
Response:
I agree he isn't the sharpest but he isn't a moron. He did on occasions show the wherewithall to react in order to make important defensive blocks and react to loose balls in the opponents penalty area (assuming this is actually to do with this stat) so would either leave it as it is or maybe
80.
Passing:
This is the major conundrum for me. His passing can be very sloppy at times but then be pretty good at other times. Looking at other Rovers players for examples, I would not say his short passing stats should be above Reid or Dunn so on average I guess a high green value is probably fair (though this probably contradicts what I said earlier).
n.b. I think Warnock's short passing could be bumped into the green area as well.
Shooting:
This is actually one of his better attributes. He was limited by where and how he was asked to play but he has a decent shot on him and scored some very important goals so I would leave it as it is for the moment.
Technique:
I agree he shouldn't be higher than Huddlestone or Essien. It was the comparison with Whelan that threw me as I have not been all that impressed with him the few times I have seen him play for Ireland and occasionally for Stoke. Assuming that Huddlestone and Essien's Tech stat is pitched correctly Andrews should probably be lower but not by a huge amount.
Mentality:
I do definitely think he deserves a good Mentality rating. When he runs around he looks a bit like he is carrying a handbag (if that isn't too offensive

) but he is a trier and will run all day. I cannot fault the effort he puts in even if his other shortcomings make him pretty average.
Hope that helps a bit.