Rust in the bladder tank is not a problem. If you absolutely insist, you can flush it out like once or twice a year but don't have to.
You do not want anything between a submersible pump and its pressure switch that can block up. If there is a blockage the pump can build enough pressure to blow pluming or itself off the drop pipe in the well. That includes a venturi and the pipe from it to your pressure tank....
The placement of the venturi before the pressure tank is a very bad idea but done by dealers that don't sell properly sized retention tanks so they use the bladder tank to add some retention/contact time; which is very little.
If you don't want to shock the well annually, then you must kill the bacteria some other way, like using chlorine etc,. for the bacteria and the iron instead of air injection for the iron and then a disinfectant for bacteria. You need the correct size retention tank in either case AND the outside faucets being after the Birm filter is going to cause that tank to be very huge.