Benefits and having multiple bank accounts

So in short, i've decided to have multiple bank accounts not only so I can go self employment as a sole trader, but also take advantage of greater ethical values and budgeting tools from other banks.

How will this affect me if they decide to randomly check / monitor my bank account (which they can do for all benefit claimants especially UC)? I claim both UC and PIP.

I'm planning to leave the payment details for my existing benefits unchanged (it would be too much of a hassle to get payment details moved over). then I get another account just for self-employment, then get a third for day-to-day expenses (to help me budget). I will aim to keep as much of a paper trail as possible.

Has anyone been in a similar position and could advise?

thanks