@Steven ParksNo you should not do that.The IRS rules prohibit any direct or indirect transactions or benefit between you and your plan. 

Doing residential service work you'll most likely end up working for a lot of real estate investors and learn alot indirectly.

I am getting started in Direct Mailing Absentee Owners of 3+ units in my area.

The business would be disqualified to his IRA if his equity is >49% or if he has any kind of control over the company equivalent to a director position.Even if the business is not disqualified, there could be issues with the transaction if it creates any kind of direct or indirect benefit to the investor.

Any direct or indirect benefit between a plan and a disqualified party can result in a prohibited transaction and void the IRA, and there are many ways the IRS could find some form of benefit in such a joint venture.

What questions should I ask when property owners reply to my direct mail? (I do not plan on purchasing all cash in my direct mail campaigns - going to do typical bank financing)?- Since it's not listed for sale, do I ...

These properties are not under contract by me - is it bad for me to put the buyer in direct communication with the contract holder, or should I "gate keep" all conversations? 

Purchasing an investment property increases the level of difficulty of your tax return.Purchasing a house-hack is even more difficult.To make it even more difficult - you plan to make improvements so you have to determine which costs are currently expensed and which are capitalized.Not only have you acquired an investment property but you also acquired a personal residence.As a result, direct expenses towards your investment property and indirect expenses are deductible business expenses that can be used to decrease your net income from rental activities.With all that is said - you are trying to operate a business so I would hire professionals to help you with your tasks.

To be successful in direct mail, you need to send at least 6 mailers to the same list.

This stands in direct opposition to a capital intensive industry such as manufacturing where employee and owner skill may be less important than the company's fixed asset profile.While S179 is a valid strategy in the attempt to drive a taxpayer's taxable income below the 'threshold amount' so the SSTB receives the un-phased out Sec 199A deduction, a SSTB may not have the investments in fixed assets necessary to drive them below the threshold during the year unless they're already very close to the threshold.Some other ideas for taxpayers owning a SSTB to lower their taxable income:Roll taxable bonds into tax-exempt bonds.Life insurance & annuities.Real estate (it's BP after all).Oil and gas investments.Charitable gifts (including CRTs).Gifts to taxpayers with lower taxable income (powerful option is to gift a percentage of the business to a trust).If a SSTB is well above the threshold, a compelling case could be made that the business should be a C Corp in the current tax environment.