Jason: If you have all the other holes drilled in the keel, then, yes, you'll have to replace it. Holes right in line and on adjacent faces are a serious no-no. They weaken the tube too much.
As for the bolts, yes, six washers is too many. Each AN "dash" number is 1/8or two regular washers. If your current bolts are too long, go down one "dash" number. If you have AN 3-26A now, get some -25A's. I think we switched to those for our AEROTEC hardware kits after awhile, for just this reason.
Just to confuse you more, the correct length in AN4 really IS -26A for this type of assembly! You'll use this size for your rotor head plates, angle brace attachments, etc.
I'm glad you reached my ladyfriend when you called. She's never there when I call...