3d printing beginer. Will this work for me?

I have been thinking about getting a 3d printer for some light manufacturing. I have come across this printer (http://www.monoprice.com/product?c_i...seq=1&format=2 ) and its a clone of the flash forge creator, that is apparently made in the same factory.
So that leads me to my question. Will this be a good printer for what im needing? Im needing to make about 400 of these half tubes. (heres a link to the part i designed.) https://tinkercad.com/things/cZbN1cOfTzl
Im worried that the printer will not be able to print the tapered keyway, and key on the part which is about 2mm in width. Can printers print detail this fine? I have seen that printers have a resolution of 0.05mm. Does this mean the printer should be able to print something with this precision?
With the printer printing in ditto mode all 400 prints should be completed in about 250-300 hours. Will a printer be able to put in this many hours? Will 300 hours be full of hassle if its printing the same part constantly with the same type of filament and settings?
Thanks for reading.