X.....None of the above.
The following is IMHO (in my humble opionion)
Painting the mast will add weight that will add to the tipping forces whenever you are not perfectly up right, which is most of the time. Also a painted mast will require much more maintenance over the years.
Re-anodizing. Is it really necessary? I have never seen an anodized mast in such a state that some cleaning and a coat of wax was all that was needed to make it useful. I have a 41 year old Alspar that was stock on my boat, and granted it is not pristine, but the anodizing is mostly intact except where it has been scratched. Even the scratches have not corroded to any extent. Maybe a little oxidation that is easily cleaned, and the mast is as good as ever.
I have a tapered mast, only because I bent the Alspar.
Insurance is a wonderful thing.
Before damaging my Alspar, Lollipop w/alspar, won a Pacific Coast Championship in a 35 boat fleet, against the likes of Len Fiock, Chuck Wilson, Edwardo Grisetti, Bill Fiock and all the California Hot shots, with my 11 year old, 95 lb. daughter for crew. The next year, Lollipop, w/Alspar, and my other daughter, again 11, won the High Serria Regatta, that was a prelude to that years NACR (winds high enough to Capsize some of the names mentioned here). In addition to the above names, Bob Blake Sr. and JR., Rob Bonney, Jim Fisher, and Al Hersey were in attendance.
Sorry for the boasting,
but I want to make the point that it is not necessary to have a tapered mast to be competitive in the DS. If you have a wad of money burning a hole in your pocket, a tapered mast is nice to have. But for my money, not worth the expense for the return in preformance gained. (very very little) The advantage of the tapered mast is that it is bendier in the fore and aft direction, so it bends easier in gusts and supposedly depowers easier. I found that using free swinging and shorter spreaders, I got the same sail shapes and depowering. So the only disavantage of the un-taperded section, is the extra windage, and the heavyier mast tip. Preformance lost? about the same as one bad tack or markrounding.
My list for DS upgrades, in order of most gain to least:
Centerboard, upgrade from Stock DS board, unless you have a boat newer than 1980ish.
Sails, (even good used ones can be competitive local and regionally)
Rudder, same as CB
Hull Stiffening, if you have older, softer hull
Mast, unless you have a mast that has been hinged at the deck level. Then I would move this up to second only to CB. I have seen masts repaired by welding at that area, that are still very competive. Len Fiock has had his mast re-welded near the deck level at least twice, and it hasnt slowed him down a bit. At 75 + years old, won a race at the '05 NACR with that mast.
I think the Myth that "ya' gotta have a tapered mast to win" happened because the oldest versions of the DS came with a very desirable Proctor tapered mast. Most of the early successful sailors, were sailing with those masts. New, up and coming sailers, emulated them and when they were also successuful, due more to commitment and effort, others sought to copy them. and the myth was perpetuated.
Sorry if I got a bit off topic. I just wanted to offer another option.
Climbing sheepishly off of my soap box now........
Hope this is helpful.
Again all the above is just IMHO. worth about $.02