I transfer via ACH/wire all the time with no issues.

If the STR strategy is the only strategy that makes the property pencil, be sure to purchase in a market where the use is allowed, the use requirements are protected by in place permitting and licensing and the permissions are transferable through a sale.

So neat and precise. 

You just can't escape the transfer of (reduced) basis on 1031 or the recapture on sale unless you croak.   

If your friend bails, having the property in an LLC makes transferring shares simpler.

However, after the exchange, they want to transfer from personal name to an LLC under their Holding Company to protect their assets. 

Also, you can always cashout refi them AFTER retirement and get that money tax-free (until you sell or transfer via inheritance).Recommend you read The Millionaire Real Estate Investor, which shares the plans of several different investors.

You said a “little” money, so bear in mind if you transfer that into a self directed account the annual contribution limits are $7k plus $1000 catch up over 50 so it may take a while to get it to a point where you have enough to invest in real estate.  

Could i take any of the left over cashflow and transfer to my personal account and use it to pay the 401k loan back? 

Prices are generally cheaper, there are no caps on rent increases and there are no property transfer taxes.