I think I have most of the kinks worked out but I'm looking for software (preferably free or very cheap) to digitalize the payments and bookkeeping from the house members.

-PM Software (Propertyware or Appfolio).

Hello is it necessary to have Property Management and Accounting Software for landlords?

Use any bookkeeping software.

What's one software or system that's important to your business but that you can't stand?

Airdna is not a wildly off data point, they are the best across the board in STR data software.

Whats your security software?

The more recent buyers (primary home owners and investors) are very high W2 income earners like software engineers and physicians.  

I’m bringing a portfolio of STR clients with me and am an experienced property manager ready with all the channel management software and integrations running and wrenches already worked out, ready to build new listings and find clients for this agency.

@Bryan La If you sign up as a biggerpockets pro member you get free use of rentredi which is property management software where you can automate your tenant screening, you can run a background a credit check super easily through there and also use it to collect rent, generate a profit and loss statement, and more.