Prices and shipping

Hello,
I need your urgent help to understand few things about the prices calculations.

1. when I import product from ali, in case after import the supplier change the product price, will this price will be updated on my site automatically? if yes, how? if no, why?

2. I need to understand how to shipping cost calculated. I want to show to the clients only one option of shipping which is “FREE SHIPPMENT and on the backend to add the shipping cost to the product price. so if the product cost 40 usd but the shipping cost 90 usd so the price the clients will see is 130 usd. how can I do that? if I can’t what will be the best way to work and how to set it?

3. can I add profit on the shipping cost?

it’s very urgent.

thanks.