Non-resident with US LLC — checking everything before CPA consult

Booking an international tax CPA soon but want a quick basic overview first.

Setup: Non-US citizen, non-US resident, single-member planning to create a US LLC, digital marketing services. All work performed by me outside the US. No US employees, contractors, office, or inventory. US bank + Whop/Stripe as Payment Processor. Mostly US clients. I am a German citizen for context.

My understanding: Not ETBUS → no US federal income tax → just Form 5472 + pro forma 1120 annually. Correct?

Questions:

1. Confirming the above — non-resident, no US presence, services performed abroad = $0 tax, is that correct?
2. Wyoming vs Delaware vs New Mexico for the LLC — any reason to pick anything over the other considering I will move and live in Los Angeles within the next 3 Months?
3. Where exactly is the ETBUS line? Is having a full-time worker instantly triggering US tax? And also from the start date of employment and all income from the business?
4. Moving to the US in around the next 3 months: dual-status applies, pre-move income stays non-resident-treated, post-move becomes worldwide taxable. Right? Any timing tricks before the move (distributions, C-corp election, residency starting date)? Currently do I am a digital nomad and do not have to pay taxes as long as I do not establish residency anywhere, do not know if that affects backtracked taxes.
5. Can I run non-US client payments (e.g. Australian, EU) through the same US LLC and bank account tax-free, since work is still performed outside the US?
6. When exactly would US sales tax become due for a non-resident LLC selling digital marketing services (thresholds, which states tax services), and can I handle all client payments — US, Australian, EU, etc. — plus any sales tax / VAT from other countries through the same US LLC and bank account?

Thank you guys very much in advance, it is greatly appreciated!