Why would I put excess share of my precious capital in a mortgage to save 4% APR, when I could buy another rental and earn way more?

This is a website full of business people, and these people are not going to offer their help unless you can provide value to them, and so if they spend their precious time instead of buy houses to make more money but to help you to become a skillful investor, everything they get from you is probably going to be a few words like "thank you" or "thank you so much", but else what?

A pet owner that is clean, works from home, and dotes over their precious furry family member is welcome in any of our rentals. 

Asking a investor for POF or to sign an NCND is the only way to protect a wholesaler's interest and from  WASTING precious amounts of time. 

. – private lending)Tax lien certificatesLimited partnershipsLLC’sSub-C corporationsReal estate optionsSome types of precious metals… and the normal investments like stocks that your normal IRA can invest inBasically, this opens it up so you can buy investment real estate with your IRA… or be a private lender in real estate.Are There Restrictions?

(I know precious few good-quality 'part-time agents.')

Is she correct or is she just trying to prevent me from purchasing so she doesn’t lose out on precious commissions?  

Any sweat equity work like repairs has to be done by a non disqualified party; therefore, you cannot do repairs on real estate owned by her IRA.The lenders listed on the following link will loan to an IRA or a solo 401k. https://www.biggerpockets.com/blogs/3441/51027-nonrecourse-loan-debt-for-self-directed-solo-401k-investment  Following are the similarities and differences between the solo 401k and the self-directed IRA.The Self-Directed IRA and Solo 401k Similarities Both were created by congress for individuals to save for retirement;Both may be invested in alternative investments such as real estate, precious metals tax liens, promissory notes, private company shares, and stocks and mutual funds, to name a few;Both allow for Roth contributions;Both are subject to prohibited transaction rules;Both are subject to federal taxes at time of distribution;Both allow for checkbook control for placing alternative investments;Both may be invested in annuities;Both are protected from creditors;Both allow for nondeductible contributions; andBoth are prohibited from investing in assets listed under I.R.C. 408(m).The Self-Directed IRA and Solo 401k DifferencesIn order to open a solo 401k, self-employment, whether on a part-time or full-time basis, is required;To open a self-directed IRA, self-employment income is not required;In order to gain IRA checkbook control over the self-directed IRA funds, a limited liability company (self-directed IRA LLC) must be utilized;The solo 401k allows for checkbook control from the onset;The solo 401k allows for personal loan known as a solo 401k loan;It is prohibited to borrow from your IRA;The Solo 401k may be invested in life insurance;The self-directed IRA may not be invested in life insurance;The solo 401k allow for high contribution amounts (for 2016; the solo 401k contribution limit is $53,000, whereas the self-directed IRA contribution limit is $5,500);The solo 401k business owner can serve as trustee of the solo 401k;The self-directed IRA participant/owner may not serve as trustee or custodian of her IRA; instead, a trust company or bank institution is required;When distributions commence from the solo 401k a mandatory 20% of federal taxes must be withheld from each distribution and submitted electronically to the IRS by the 15th of the month following the date of each distribution;Rollovers and/or transfers from IRAs or qualified plans (e.g., former employer 401k) to a solo 401k are not reported on Form 5498, but rather on Form 5500-EZ, but only if the air market value of the solo 401k exceeds $250K as of the end of the plan year (generally 12/31);When funds are rolled over or transferred from an IRA or 401k to a self-directed IRA, the amount deposited into the self-directed IRA is reported on Form 5498 by the receiving self-directed IRA custodian by May of the year following the rollover/transfer.Rollovers (provided the 60 day rollover window is satisfied) from an IRA to a Solo 401k or self-directed IRA are reported on lines 15a and 15b of Form 1040;Pre-tax IRA contributions on reported on line 32 of Form 1040;Pre-tax solo 401k contributions are reported on line 28 of Form 1040;Roth solo 401k funds are subject to RMDs;A Roth 401k may be transferred to a Roth IRA (Note that from a planning perspective, it may be advantageous to transfer Roth Solo 401k funds to a Roth IRA before turning age 70 ½ in order to escape the Roth RMD requirement applicable to Roth 401k contributions including Roth Solo 401k contributions and earnings.)

If you do decide to do STRs in 29 Palms, please encourage your guests to respect the neighborhood, be quiet, keep garbage under control, and limit light pollution to keep those precious dark, star-filled skies. 

If you were paying for something say precious metals... often do a EFT to the company... some people do wires when buying a vehicle/etc vs showing up with cash.