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Joe, this has nothing to do with stepping on toes, it's just learning how to use your machine properly. Moving slow on the handwheels? Absolutely. Running at 200rpm with a 1/2" cutter is counter-productive unless you are working stainless or some other fairly hard or tough material (in titanium you might be down at 70rpm and pushing it). This is not from a time per piece job-shop point of view, this is just proper tool surface speed. You are no less likely to hit the vise or go the wrong direction with the spindle running at 10 or 10,000rpms. Spindle speed has nothing to do with being careful. The object here is to remove the metal at a speed that lets the cutting tool shear cleanly instead of scraping the metal off. It produces less load on the cutter in that way, for one. Also consider this... your cutter makes two turns for 1/16" of feed or runs at a speed where it makes eight turns in that same 1/16". Obviously the cutter running faster is going to be under less load as four times the cutting edges are removing the metal, taking much smaller bites. Try this, put a hunk of scrap in the mill (or lathe). Start a cut with a 1/2 or 3/8" endmill at lowest speed, go a little ways and stop. Now without changing depth of cut or feed rate, go up the next speed. Keep this up until the chips begin to turn blue and look at how the finish improves and also note how much better and smoother the machine seems to cut at the higher speed. Not trying to beat you about the head and shoulders, just trying to show you a better way to do things that will improve your abilities and make your work look a lot more professional.
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