Give Tenant B a few months rent at the same rate (no rent on the additional space) and commence rent on the whole space after their concession period.

The agreement also includes language that if tenants are unable to pay the decreased amount of rent between now and the end of the year, eviction proceedings and garnishment of wages for the full amount due will commence the following day.

I think your only hope at this point would be to wait to see if they fail to pay into the plan and for the Trustee to file a motion to dismiss, then commence FC. 

Also, you don't need to invest an amount equal to the purchase price or your original basis, but you can invest an amount equal to the ADJUSTED basis at the time that the 30 month period commences.

The landlord, or any person authorized to enter into a rental agreement on his or her behalf, shall disclose to the tenant in writing at or before the commencement of the tenancy: (a) The name and address of: (1) The persons authorized to manage the premises; (2) A person within this State authorized to act for and on behalf of the landlord for the purpose of service of process and receiving notices and demands; and (3) The principal or corporate owner.

Following are the similarities and differences between the solo 401k and the self-directed IRA.The Self-Directed IRA and Solo 401k SimilaritiesBoth 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(mThe 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 companyThe 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 (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 2018, the solo 401k contribution limit is $55,000, 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.)

The other practical aspect of this discussion that needs to be observed is that if you have a complicated asset protection set up, once there is a significant claim in which you desire the setup to protect you, their is a good chance it will be put under a microscope once litigation commences. 

Should I be asking for additional deposit to secure my property 30 days in advance of commencement of the lease?

(f) An adequate number of appropriate receptacles for garbage and rubbish in clean condition and good repair at the commencement of the tenancy.

If from someone other than your spouse, then you will need to commence annual IRA distributions by December 31 of the year following the IRA owner's death, and the distributions will be based on your life expectancy which could affect your investment decisions.