Problems with doing a financial model for an e-commerce startup with very volatile earnings and others?

Hi, so I know this may not be the most appropriate forum to ask for a financial modeling-specific question, but I thought I can just give this a try.

So I need to do a financial model for Seagroup, which is an e-commerce tech startup based in SE Asia, but it is listed in the NYSE already (SE). I got their 2017-2019 Annual Reports data from their investor relations page and I have some line items that I have difficulties in modeling: 1. They have very volatile revenue growth YOY (74%, 168%, 467%, 204%) 2. They pay very low tax rate (13%, 2%, 4%,etc) on the IS. Is it because they have net loss so they get deferred tax asset? But I don't know that the tax is treated with a rate as low as that in the IS.
3. They have bigger interest expense than the debt ( say, they have around $2000 (mio) of short-term and long-term borrowings combined, but $26,000 (mio) interest expense on IS)

So my question is, how do you think I should approach these items in the projection for modeling and any idea what can cause #2 and #3? Thank you!