Hi.
Love the pen.
I too am slightly, no sorry totally obsessed with turning pens! I love acrylics which is weird as I thought I would only ever turn wood.... I know naive!
I have a couple of these blanks myself, but I haven't turned them yet. (I got them from australia .... timberbits i think A1 pen kits on fleabay)
I've also got some of those pen kits too (after seeing yours I might add!)
On the subject of painting holes.. I do to most of mine... just incase, I think there's nothing more disappointing than finishing a pen, and then realising I can see the tubes.