When it comes to feeds and speeds along with what others have responded with you can find a starting point and then the setup man or operator will need to adjust some but not all the tools.
This has to do with the shape of the part, clamping, length of the holder and the tool.
A safe point to start is 4 X SFPM (Surface Feet Per Minute)/Diameter of the Tool = RPM
For plastic I would start with .003 X Number of Flutes = Feed Rate.
Use 2/3 width of cutter for step over cuts and 1/3 diameter for Z depth of cuts.
You will be able to adjust safely up from there and be aware of possible melting in to Heavy of Cuts and RPM's.
My Response to "It's Close Enough", "Is Your Tool Box and The Door Close Enough?"