Investing with a Partner but not forming LLC

Hi BP community, I'm currently working with a partner to start investing in our first RE rental. I've been reading up on a lot of the forum posts (thank you all for the amazing content) and understand that many investors are not forming LLCs due to lending complications. Right now we're leaning towards taking a joint investment mortgage together under our own names.

If we do go down that route, was wondering about the following:

- Has anyone done the above, and if so, how do taxes work between you/your partner(s) at year end?

- I've read about many quitclaiming to LLC eventually, but the lender we're working with has said that could trigger due on sale. If we take out an umbrella insurance policy, is there any long-term need to still quitclaim to LLC?

- Any other advice on downsides to going down this route vs. LLC formation?