Stock rb25det is slow. No way would you take the turbo off. They definitely don't make a shit tonne of power as you seem to think.
Stock rb20det is horrendously slow, removing the turbo would be the work of an absolute idiot in this case.
Of course you can unbolt the turbo and put a set of na headers on there. But don't. You can get to know important aspects such as the "turning radius" you are concerned about just fine with the car standard.
Finally, What's the "oil pan problem" you are going to fix?