The analyses of a text #1

The narrator recalls his adolescence.
He was an apprentice for Mr. Spenlow.
He and Mr. Spenlow's only daughter Dora fell in love with each other, but after Mr. Spenlow's sudden death, she moved in with her two aunts and confined herself there.
Her best friend Miss Mills had made the role of a messenger between them.
And He made an appointment with Dora's aunts to visit them through correspondence.

....................................................
It was a great augmentation of my uneasiness to be bereaved, at this eventful crisis, of the inestimable services of Miss Mills. But Mr. Mills, who was always doing something or other to annoy me - or I felt as if he were, which was the same thing - had brought his conduct to a climax, by taking it into his head that he would go to India. Why should he go to India, except to harass me? To be sure he had nothing to do with any other part of the world, and had a good deal to do with that part; being entirely in the India trade, whatever that was (I had floating dreams myself concerning golden shawls and elephants' teeth); having been at Calcutta in his youth; and designing now to go out there again, in the capacity of resident partner. But this was nothing to me. However, it was so much to him that for India he was bound, and Julia with him; and Julia went into the country to take leave of her relations; and the house was put into a perfect suit of bills, announcing that it was to be let or sold, and that the furniture (Mangle and all) was to be taken at a valuation. So, here was another earthquake of which I became the sport, before I had recovered from the shock of its predecessor!
[David Copperfield by Charles Dickens]
1. I'd like to know if "have a good deal to do with something" is used in present English.
2. I think "that part" indicates the following noun phrases.
So I was wondering why it is "that part," not "those parts."
3. And I'd like to "was bound for India" is implied before "with him."
Thank you in advance for your help.