1) An entity is a separate taxpayer! An entity needs to timely elect MTM AND qualify for TTS.
2) Yea, brokerage, bank, and other trading business accounts and assets need to be titled properly.
3) Generating trading profits is applicable to investors, hobbyists, non-trading businesses, and trading businesses. Being that is YOUR SOLE PURPOSE, the IRS may not view that as intent to operate a trading business with an intent to provide a primary or supplemental livelihood.
I'm just a lowly full-time futures (day)trader who has operated through an S-corp for many years, doing my best to receive all the deductions, credits, and benefits I am legally eligible for given my business and personal structure, while paying my US tax obligations according to the rules set forth by the US-IRS.
IOW, I know nothing.

Seek professional advise for your plans and circumstances.