Some of us do sub2 deals, but, given the various points you referenced, it's going to be difficult to adequately address your question without asking several other questions. I'll resist that temptation for now. With that said, I'll take a shot at answering. Disclaimer: I'm not an attorney or CPA, so I'm not giving official legal advice or tax advice.
It sounds like you're talking about doing sub2 deals with an owner-fi wrap exit strategy. One way of doing it is to get the original owner to deed the property to a trust, your company "buys" the beneficial interest in the trust, and then the trust wraps it to your owner-fi buyer. A bank will likely require a tax id number for the trust in order to let you open a bank account for the trust, so, if you obtain a tax id for the trust in order to open the bank account, you can then file an independent tax return for the trust. I'm guessing that your actual profit will fairly low after collecting the loan payments from your owner-fi buyer and then paying the underlying note each month, so the trust's tax burden each year shouldn't be that big.
There are LOTS of ways to sub2 deals. What I've described above is just one possible way of handling one of many aspects of a sub2 deal. Everyone reading this should understand that sub2 deals have a lot of moving parts and can be quite complex, so proceed with caution. I hope this helps. Good luck!