Jeff,
I ran your numbers with your specs and came out with the same data.
Next, for the CE150, I had to shorten the arrow to 28 3/8" and came up with 67.3 which is .2 from your bow.
As for the MFX500, I had to shorten the arrow down to 26 5/8 to get the numbers close.....66.8 compared to the bow's 67.1. Pretty short arrow since your draw is 28".
I then used the MFX400 and to get the numbers close, I came up with an arrow length of 28 3/8". In this case, I suppose the 400 would be a better choice.
You are using his calculator OK, but just need to play with arrow length. If you definitely want an arrow length of 29", I quess you'll have to play with the point weight. As for the MFX, a different spine arrow was in order since the 500 had to be really short.
By the way, the instructions in the calculator says that for an external footing you do put the insert weight in the "insert box" and the footing weight in the footing box. Just for grins though, I put "0" in the insert box and the insert wt + the footing wt in the "footing wt box" and the final numbers came out the same. Therefore, I quess it doesn't matter.
Anyway, Good luck....Bob