Questions regarding setting my international store and rerouting customers

[husaink]

I have been running my store bnbags.com in my home country of Pakistan for a few years now. I now want to launch the international version of my store with different prices, currency and payment options. I already tried using Shopify Markets for this so i do not need a new store but it did not work as I need to offer different payment options to international and local customers and Markets does not allow that. So I was thinking that I would transfer my local store to the a new bnbags.pk domain and use bnbags.com as the domain for my international store. Before i set about doing this, I had a few questions which would be great someone experienced can answer:

1. How do i reroute customers from Pakistan who are used to the old .com domain to the new .pk domain? Do i need an app for this?

2. What is the best way of syncing the inventory of the two stores?

3. Do i need to create a subdomain or link the two stores in any other way other than for the inventory? I'm not quite sure i understand how subdomains work. Are they needed in my case? What will be best for SEO?

Thanks a bunch!

Husain