Agree with the cooler. I use a laminova cooler so using coolant rather than air to cool the oil. Much small than air coolers and fits easier in the engine bay especially with a turbo car due to intercoolers and boost pipes.
I used a breather filter on my car at the start and would not recommend it on a forced induction car. On the rollers you could see a lot of oil mist coming from it shortly follow by my crank seal failing. I suspect this was caused by high crank pressures during the mapping. Fitted a catch tank with 2 breather filters and although I dont get huge amounts of in the tank I do get something. Usually oily condensation that I would definitely not want back in the inlet.
Also, oil vapour can be flamible and venting this next to very hot objects like manifolds and turbos could cause a fire.