The analyses of a text #1

The narrator recalls his adolescence.
After the funeral of his old nurse Peggotty's husband, he visited Peggotty's elder brother Mr. Peggotty's house to dinner.
Mr. Peggotty's nephew, adapted son Ham was due to come with his niece, Ham's fiance Em'ly but Ham came to alone.
Em'ly fled with the narrator' best friend Steerforth with leaving a letter to Ham.
The narrator was taking a walk the next day morning when he saw Mr. Peggotty and Ham on the beach.
Mr. Peggotty said to him he, Peggotty, and Ham is going to move to new house.

Here "it" refers to the present house.

....................................
'My wishes is, sir, as it shall look, day and night, winter and summer, as it has always looked, since she fust know'd it. If ever she should come a wandering back, I wouldn't have the old place seem to cast her off, you understand, but seem to tempt her to draw nigher to 't, and to peep in, maybe, like a ghost, out of the wind and rain, through the old winder, at the old seat by the fire. Then, maybe, Mas'r Davy, seein' none but Missis Gummidge there, she might take heart to creep in, trembling; and might come to be laid down in her old bed, and rest her weary head where it was once so gay.'
I could not speak to him in reply, though I tried.
'Every night,' said Mr. Peggotty, 'as reg'lar as the night comes, the candle must be stood in its old pane of glass, that if ever she should see it, it may seem to say "Come back, my child, come back!" If ever there's a knock, Ham (partic'ler a soft knock), arter dark, at your aunt's door, doen't you go nigh it. Let it be her - not you - that sees my fallen child!'
[David Copperfield by Charles Dickens]
1. I'd like to know if "reg'lar" means "regularly."
2. I'd like to know if that means "in order that."
3. I'd like to know if "partic'ler" means "particularly."
4. And I'd like to know what "doen't you go nigh it" means here.
Thank you in advance for your help.