Do I HAVE to let turbotax into my schawab account? They,Schawb told me not to do it?

You don't have to "let TurboTax into" your Schwab account, but then you can't import your Schwab 1099 tax information into TurboTax. You have to enter the information manually.

I do the import from my broker.   WARNING for anything you import   compare it to the actual documents.   sometimes things go wrong or are not imported but the IRS gets the info so you get a letter from them.  saying you owe some additional taxes.  

TT does not get full access to your account only the tax documents. 

TurboTax does not access your account.  The brokerage company has to set up a separate data fie coded by them, for download purposes.  The program then opens a portal which allows the data from that file to flow in the program.  The program does not look at any individual transactions from your brokerage account.