(I’d probably try to buy from the multi-member LLC to show the IRS I’m a new owner who hasn’t used the property a a rental before making it my primary to preserve 100% tax free status in the future.

It is very close to what we’ve aimed as we are also full time professional at day and want to get on real estate as a way to invest and preserve wealth

If you strategy is to build a rental portfolio as fast as you can then, you want to refinance at the highest available leverage. (75%) That allows you to preserve your capital so you have down payment money for your next deal.

If you have more available cash and other income, you might start with more emphasis on appreciation/capital preservation vs. the opposite. 

Is it possible for them to add me (the child) to the title of the new CA house while preserving the 1031?

So, I have to preserve some of that cash flow, but given the equity we have, I'm trying to figure out how to manage these goals.

I'd look at markets where you can not only build but you can build with enough equity to BRRRR out of the property and preserve cash. new construction is just one strategy. in columbus there are about 12 submarkets that you can do this in. we define them by their school districts. some you can build and get 40%+ equity like hocking county which is a vacation rental market for airbnb. some 500 square foot cabins are going for $350k there it is absolutely insane. chart below shows it all. this is for columbus ohio submarket analysis. 

They are there for your protection and to preserve the value of your investment. 

You preserve the money you made in the purchase with the rehab of the property. 

Do you want to preserve capital or grow it?