I was thinking of rewriting or altering our parent LLC agreement to have my wife allot me some of her shares so I have a majority stake, but wanted to get thoughts on whether this is the best route or is there's other avenues I haven't thought of?

I’m wondering what zip code it’s located in, how you acquired it, how you funded it, how you added value, what loan you refi’d it into, and how are you renting it now.

I personally use Hospitable for hosting, it integrates with my Schlage Encode lock and automatically generates door codes.

Also, any recommendations for good zip codes to look into?

This can happen due to the Assessor not updating the records when additions are done, or when an unpermitted (illegal) addition/alteration is done. 

I probably have a promo code I could give you if the BP one isn't good anymore but I used the free version for quite a while with success.It's also pretty decent at pushing listings out to some of the major rental sites.

I’m looking at multi family units and mainly curious if certain zip codes tend to have more troublesome tenants vs others. 

The areas you mentioned have opportunities, I also like zip codes 93710, 93728, 93704 as there are a lot of homes in the price range you mentioned. 

The best way I know is to use airdna.co for some local/zip code level research. 

As long as they are to code and removable, I wouldn't have a problem with it.