Highly embarrassing to ask this of such seasoned bakers, but I'm not finding definitive answers in books or the forums. I'm about to do my first true stacked cake--others have been combination stack/tier and used plastic separator plates. These will be 12", 9" and 6" rounds covered with buttercream and fondant. Ribbon edge rather than piped or fondant border.
Question #1: Do cardboard cake boards need to be covered with something if the cake is constructed 36-48 hours before cutting?
Question #2: How many dowels do I need to use?
Question #3: Does sharpened center dowel really insert with ease or is there danger of the resisting cardboard buckling?
Question #4: My charts say this will serve anywhere from 60-75 people, depending on the chart. When I look at the cake boards that seems optimistic. This will be a party cake.
#4... You didn't mention how many people you needed to serve, but I think that this cake should easily feed 60 'party' servings.
#3... A sharpened dowel really does insert with ease.
#2...I use 6 for both the 12" and 9" (you could get away with 4 for the 9")
#1...I don't cover my cardboard with anything, but the most my cake has ever stayed was probably about 8 hours. I know some people cover with saran wrap, but I'd think you'd be ok. Hopefully someone else will be able to answer that better for you.
Yep, ditto for me too, except I have used uncovered cake boards for cakes that were held for two days - had no problem whatsoever with that.
Don't be afraid of hammering that pointed dowel through all the cakes. It will work as long as you sharpen the point and position yourself above the cake so you are hammering straight down and not at an angle. I stand on a chair! 
I am not a seasoned baker, but I have done quite a bit of stacked cakes and I can tell you what I have discovered.
Question #1: Do cardboard cake boards need to be covered with something if the cake is constructed 36-48 hours before cutting?
I like to cover them in plastic wrap otherwise your cardboard will be soggy.
Question #2: How many dowels do I need to use?
From the Wilton website:
"The general rule for the number of dowel rods to use is: the larger and more numerous the tiers, the more dowels needed. If the tier above is 10 in. or less, use six 1/4-in. wooden dowels. Use 8 dowel rods for 16 in. and 18 in. cakes; on these larger tiers, use 3/4-in. plastic dowel rods in the base tier. When using white plastic dowel rods that are wider and provide more support, the number needed may be less."
http://www.wilton.com/wedding/makecake/building/dowelrod/dowel_tiered.cfm
Question #3: Does sharpened center dowel really insert with ease or is there danger of the resisting cardboard buckling?
I have never had any problems. Just make sure the end is very sharp (I use a pencil sharpener I have only for cakes), then gently tap it in with a mallet or hammer. When it reaches the cardboard, you will feel it but a firm tap will push it right through.
Question #4: My charts say this will serve anywhere from 60-75 people, depending on the chart. When I look at the cake boards that seems optimistic. This will be a party cake.
I would say at least 75 people. The taller your cake is, the more portions you get out of it since your slices can be smaller. The taller, the more cake. I hope that makes sense?
I cover the boards with the glad press n seal. It sticks on very well by itself and then I don't give a second thought to whether the boards will get soggy.
Just my 2 cents.
Quote by @%username% on %date%
%body%