I was wondering, are any of those travel expenses tax deductible?

Absent that, the big differences will be which forms you report the income, your ability to deduct business expenses against the income, and applicability of self-employment taxes. 

Does anyone have strong views on whether on rental properties ALL the interest from a cash-out refinance can be tax deductible (even if the cash is invested to buy or fix up another property), orOnly up to the original loan amount, orSomething else.Currently assuming 1) but not at all certain...

(Doing this correctly, you’ll be able to get a deep tax deduction) 

Purchasing allows you to save on future rental costs and depreciate the asset or use Section 179 for a full deduction. 

Big chunk of your life insurance premium goes to pay insurance salesman commissions so you have negative return from day one.Pay less taxes: contributions to an IRA are tax-deductible so it will help you pay less in taxes.

If you hire a contractor , you deduct what the contractor charges .

If you are going conventional, they will need 2 years of tax returns, no way around it.We will use your "net income" after all deductions for 2022+2023 and divide over 24 months.

Insurance would cover it, I would pay the deductible, and no assets would be lost.If you are in an area like San Diego where people are more likely to sue, a judge is more likely to find you guilty, and the payout is expected to be higher, you may consider an umbrella insurance policy.

Travel and meals (50%) are deductible.