This guy explains it really well. Slow speeds are what burns and breaks bits. And your feed speeds are what I run my machine at so you will have no problem at that speed. I think you may want more stepover but that is personal preference. This stuff is not an opinion its a technical specification that has one right answer. That answer may be hard to nail down due to material hardness and moisture content but the math for chipload will not be far from the specs that are given for each bit.