can someone get to this huge amount of biz and stay internet incognito?

Not a lawyer, not legal advice, just a guy on the internet. 

Plus if you need repeat the process down the line you will have a suitable template.Using a generic one from the Internet increases your risk when / if things go wrong.

Now, as the internet only improves with developments such as Starlink, where anyone with a laptop will be able to connect to the internet worldwide.

Do you really want to trust some doc hacked off the internet?  

I might recommend an internet search for "CPA 990-T {your city/area}"In addition to the federal tax, you will likely have a corresponding California tax and/or tax in the state where the income is generated.  

As far as needing the internet service to connect the camera I asked one of the tenants if I could hook it up to their wifi to help with the issue and they were happy to help.

Internet & cable. 

I run my short-term rental business out of my personal house under my LLC, which I drew up a lease between that creates an agreement to pay for utilities, internet and common household products I need to function my business in exchange for the property.

I see some people who only do internet advertising/ social media and email but it seems expensive to scale and not a super proactive approach.