How to correctly set up international shipping and taxes for dropshipping?

[Glam2]

Hi,

I'm about to go live with my website and I just want to make sure i'm collecting all the required shipping & any other taxes properly, if anyone here can help!

Background: I'm dropshipping to all countries using Aliexpress, but i'm based in Singapore. I don't have a physical location or personally hold inventory/make shipments. All my products will be dropshiped directly by the Ali Express retailer to the location from where the order is recieved. I am terribly confused and unsure of how do i set up affordable shipping rates for the different countries (such that buyers are not put off!) and ensure that my products are delivered ideally within 2 weeks anywhere in the world! 

Separately, is there any other tax apart from the shipping tax that i should worry about and charge customers? - If so what tax and how do i set it up in default?

Will be so...so....grateful for your help with the above! 

Cheers.