This is strictly a perception thing in my opinion, not a legal issue.Also generally speaking the code of ethics for licensees makes things like wholesaling a bit of a gray area in terms of who all gets a piece of the pie (broker's comission split and other distribution of earnings)

@Harold Groetsema - by that you mean that if you're personally taking a distribution from your checkbook IRA, you have to send the funds and a distribution request to your custodian who then sends the funds to you personally. 

It is just a different way of building retirement savings.If you were to cash out the plan, you will do two things that are negative right off the bat; significantly reduce the amount of capital you have to invest with through state and federal taxes as well as a 10% penalty if you are under 59 1/2 years old, and likely significantly increase your marginal tax rate on all of your income in the year in which you distribute a lump sum from your plan to yourself.

How is the risk generally distributed? 

From what I've read Amazon had broken ground on a new distribution center in Fresno.  

Now when we sell this subject property,  should we distribute proceeds to each partner of LLC and they handle their taxes themselves OR, should we first take the sale proceeds into the LLC which will call for capital gains tax and then distribute funds to all partners and then again they may have to pay taxes as their income for the year on the profits.What is the best approach in such scenario.

Typically, employer sponsored plans can not be rolled over until you are either no longer working for this employer or reach a retirement age.To find out for sure contact your employer (or plan administrator) and inquire with them if they allow for "in-service distribution". 

@Sam MillerFollowing 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(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 (Checkbook IRA) 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.)

All investor funds distributed at sale closing.

An LLC gives you limited liability without imposing double taxation on you, the way a corporation would, where the corporation is taxed and then you are taxed again when the corporation distributes profits to you.