The analyses of a long text #2

The narrator recalls his adolescence.
His grand aunt and her distant relative Mr. Dick came to London after her going bankrupt.
He works as the secretary for Doctor Strong in his spare time, who was the head master of the school the protagonist went to.
One day, His best friend Agnes and her father, a local lawyer, Mr. Wickfield visited Doctor Strong.
And the next day, Mr. Wickfield's partner Uriah, who was once the clerk for him, came too.
One night, the narrator finds Doctor Strong, Mr. Wikckfield, and Uriah is together in a room.
Mr. Wickfield and Uriah have had a strong doubt that Dr. Strong's young attractive wife has a love affair with her cousin Mr. Maldon, and Uriah insinuated it to the narrator a few days ago.

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'As you didn't understand me, Master Copperfield,' resumed Uriah in the same officious manner, 'I may take the liberty of umbly mentioning, being among friends, that I have called Doctor Strong's attention to the goings-on of Mrs. Strong. It's much against the grain with me, I assure you, Copperfield, to be concerned in anything so unpleasant; but really, as it is, we're all mixing ourselves up with what oughtn't to be. That was what my meaning was, sir, when you didn't understand me.' I wonder now, when I recall his leer, that I did not collar him, and try to shake the breath out of his body.
'I dare say I didn't make myself very clear,' he went on, 'nor you neither. Naturally, we was both of us inclined to give such a subject a wide berth. Hows'ever, at last I have made up my mind to speak plain; and I have mentioned to Doctor Strong that - did you speak, sir?'
This was to the Doctor, who had moaned. The sound might have touched any heart, I thought, but it had no effect upon Uriah's.
'- mentioned to Doctor Strong,' he proceeded, 'that anyone may see that Mr. Maldon, and the lovely and agreeable lady as is Doctor Strong's wife, are too sweet on one another. Really the time is come (we being at present all mixing ourselves up with what oughtn't to be), when Doctor Strong must be told that this was full as plain to everybody as the sun, before Mr. Maldon went to India; that Mr. Maldon made excuses to come back, for nothing else; and that he's always here, for nothing else. When you come in, sir, I was just putting it to my fellow-partner,' towards whom he turned, 'to say to Doctor Strong upon his word and honour, whether he'd ever been of this opinion long ago, or not. Come, Mr. Wickfield, sir! Would you be so good as tell us? Yes or no, sir? Come, partner!'
'For God's sake, my dear Doctor,' said Mr. Wickfield again laying his irresolute hand upon the Doctor's arm, 'don't attach too much weight to any suspicions I may have entertained.'
'There!' cried Uriah, shaking his head. 'What a melancholy confirmation: ain't it? Him! Such an old friend! Bless your soul, when I was nothing but a clerk in his office, Copperfield, I've seen him twenty times, if I've seen him once, quite in a taking about it - quite put out, you know (and very proper in him as a father; I'm sure I can't blame him), to think that Miss Agnes was mixing herself up with what oughtn't to be.'
[David Copperfield by Charles Dickens]
1. I'd like to know what "the grain with me"
2. I'd like to know what "I've seen him twenty times, if I've seen him once."
3. I'd like to know what "quite put out" means.
4. And I'd like to know why it is "proper in," not "proper to."
Thank you in advance for your help.