I have a very full birch in my frond yard. I had some other (oaks) topped but they said I shouldn't top the birch because It will kill it. I also asked about trimming the birch and they suggested leaving it alone or cutting it down commpletely.

I don't know why you would mess around with a birch. Yes, you don't top it, you don't trim it and if you don't want, cut it down.

Is it interfering with landscaping plans, a house reno, or whatever