I'm looking for some resources where I can learn how to properly analyze deals, especially larger and more complicated deals with multiple sources of financing, multiple tiers of investors, rental income to consider, vacancy rates, etc.

Good thing about personal loans is there is no LTV/CLTV involved its based off off income and credit.

My wife and I don't want to jeopardize our current mortgage (our children have no income), and we are worried that going through with this HELOC might cause our lender to see that our children are now on the deed, thereby invalidating our current mortgage and causing problems with the HELOC as well.

If you plan to hire a property management company, your most likely going to simply be an investor and just get passive income.

Some investors who acquired investment properties with the intention to flip made a pivot to rental income when they found that they were not able to sell the properties at a favorable price because higher rates priced out many of their potential buyers. 3.

You need "similar" income to offset, otherwise it just carried over. 

If you had a turnkey apartment building with 5+ units the value is based on the income not comparable sales.

If you have  a owner occupied homesteaded  duplex in Texas , and you have rental income from one side , can a creditor do a forced sale on the homesteaded duplex ?

No income No doc . 

You’ll have some requirements to show future income, but it might be the easiest “next move.”I wish you all the best.