When you do so you can make investments inside of the IRA to acquire real estate or any other type of alternative investments (the only exception would be collectibles and life insurance contacts).

I've checked out the pricing of Bitrix24, and the free option (<5 GB storage, to time management tools, no external users) seems to be a good choice for smaller teams.

There's pros and cons to both strategies, but the truth is this is entirely a personal choice.

On another note, if you are looking to have access to some of the retirement funds without having to pay taxes, you could open a solo 401k plan, which can be directly invested in real estate, and then you can borrow some of the solo 401k funds.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;Both are prohibited from investing in assets listed under I.R.C. 408(m); andNeither may be invested in your own business.  

We are using the title company of our choice, and the earnest money is in escrow with that title company.

I am wrestling with the choice of saving up for my primary residence, which will take time, versus starting to invest now.

The choice is all yours.

After sharing your feedback with my lender he responded with an alternative for the ARM he proposed for years 6 - 10.  

If you are trying to use profits for other means then keeping the house in the 401(k) might not be the right choice for you.You can certainly cash out these plans now, take the tax hit and invest in real estate.  

Alternately, if you are in a hot market, have no money, aren't willing to work your tail off, have no skills to add any real value, etc. then you should have no reasonable expectation of making any return at all, and if you do then it is probably coming via ill gotten ways.Wasn't there a Led Zeplin song with lyrics something like "...and he's buying an escalator to heaven"  Jay?