Hi, I have been through your services for the past 2 years. Like previous times, I have sent emails to 2 different members of your team to proceed with filing Forms 5472 / 1120, for 2 and potentially 3 different LLCs. Unfortunately, I didn't receive any answer. Who should I contact to go further? Thank you

Hi, Quick introduction, I'm a Swiss citizen living in Taiwan, and I have an LLC in Delaware. I mainly do digital marketing. This year, I started working with a US-based online platform to sell my sales tunnels on the US market. When I signed up with them, they asked me to choose and fill out a form, W8, W8-BEN, W9, etc.... On the advice of the platform's account manager, I filled in a W9. But I'm not sure if I should have done the W8-BEN instead. Just in case it makes a difference: I don't collect money directly from customers, the platform does that, and then I transfer the funds. My questions are: -In my case, W8-BEN or W9? -Will I be taxed? If so, by what percentage? Is this percentage based on total sales volume, or only on the benefits part? Sorry for the long message. Thanks for your time!