There’s far more work inside IR35 than outside.

If you’re going to work inside, just use an umbrella. The margin they take is minimal and they make life so much easier.

If you’re going to run a limited company, you have to actually run a limited company. There are horror stories on the contractor forums where HMRC have taken a dim view of contractors whose companies are essentially run by their accountants. I can’t remember what the term associated with it is but definitely an area to be careful with.