She says she loves cleaning our house because there is no clutter like a primary residence.We put in new super capacity washer and dryer as doing the laundry is the biggest bottleneck and she does all this on site and remakes all the beds.

Very similar to my own plan.In regard to reaching your goal faster, the bottleneck seems to be saving for the down payments.

Just seems like I'm bottle necked.

If the realtor is the bottleneck, then fire them and get a more investor friendly agent who understands the need for speed and availability. 

Although taking myself out as the bottleneck is an admirable goal, I don't think we manage a large enough portfolio to start thinking about internal growth with more employees (i.e. a VA or administrative assistant)So instead I thought I'd look at my process and analyze the waste using a KAIZEN or "continuous process improvement" mindset.

Ultimately parking space and outdoor space are the bottlenecks for building larger units to house more people. 

THAT is the #1 bottle neck when it comes to REI!

we’ve already started our real estate investing journey, however our one bottleneck is Lead generation. any insight would be greatly appreciated!

Yes, to them it may be a tad of a hold up/bottle neck because they have to wait for you to approve but if you ensure that you review and approve or decline within say 24-48 hours that should help your PM to maintain your property with efficiency and in excellence without running your expenses too high in an untimely manner.

Sure, possibly, IF nothing is done to address the flaws now being discovered and highlighted, which I believe common sense dictates solutions and adjustments will be implemented to eliminate the liquidity bottleneck in the system.