I'll make one comment :

140-150sq.ft. mainsail! is to much for a 14 foot catamaran. Forget about that area. Even if you do managed to get it in the mainsail the boat will not be well behaved as the short hull are far less resistant to pitching. I know 140-150 sq.ft. sounds cool to have but I trully think this to be an illusion I would try 110-120 sq.ft first as an absolute max. My calcs suggest 7 mtr mast = 22.95, 10.17 sq. mtr. sail = 109.35 sq.ft. of mainsail and a foot of about 1.93 mtr = 6.34 ft. If we round everything of then lets say 7 mtr mast, 110 sq.ft main with 6.5 ft foot. This box is a scaled down F18 mainsail with a modern squaretop and with the boom at 0.350= 1'2" above the tramp near the mast = low. This rig is scaled to the seriously reduced dive resistance of the F14. In flat water and with this rig it will behave much like a F18. In waves the short hulls will be at an disadvantage more as the waves can not be scaled to suit the F14; that is something to just accept. To approach the F18 performance the platform + crew weight needs to approach 153 kg = 337 lbs. Thus assuming the F14 is sailed with 75 kg's skipper = 165 lbs you'll need to build the platform to 78 kg = 172 lbs.

This is all within realistically achievable specs. So if you want the short and effective route to a very decent F14. get the measurements of an F18 you like and scale everything by a factor of (F14 Length/F18 length) = 4.27/5.52 = 0.7735 or maybe 4.30/ 5.52 = 0.7790 as I don't know what the maxim F15 length is. I think a factor of 0.78 would work well and be accurate enough.

This is something I would do with one exception. I would decrease the height of the hulls much less than the ratio suggest as you'll need to clearence to stay clear of the waves. However the underwater body can be directly copied using this factor, beam locations and board locations as well.

One more comment : Be very careful of scaling down an A-cat as the ratios of this boat are completely different than most other catamarans certainly when compared to a F14.

Wouter