Few questions regarding Shopify

[Yashfeen]

Q1: is it true about Shopify that it charges up to 2% in transaction fees unless using its payment gateway?
Q2: is it charges additional costs for third-party apps and add-ons?
Q3: is it has limited scalability with 100 SKUs and three options per product?
Q4: is it has limited customization for URLs and SEO features?

[DelightCart]

@Yashfeen 
Q1: Yes, this is true.
Q2: Yes, additional costs are common.
Q3: Partially true.
Q4: Yes, there are some limitations