A few thoughts:
1) How did you confirm your chain length? Most harbor masters around here will tell you specifically how much scope you can have for your moorings actual lat/lon location. Too much and you bump your neighbors. Too little and you drag.
2) Your bow cleats should be fine. Having had boats and family boats on moorings for over 40+ years, 15 of them in the open ocean not a harbor, I find I actually prefer edge mounted cleats.
They give you two lines to have to chafe through at each cleat when you fold the eye and if they are close enough to the edge and you have enough pendant scope you get little to no chafe with them. Our current boat has a beautiful cast stainless bow plate with integral chocks that are very, very smooth. I get MORE chafe with this set up than I did on my Catalina's with edge mounted cleats. The distance between the chock and cleat allows for stretch and rebound. This is what causes chafe, the movement. With edge mounted cleats you get little to no stretch and rebound effect thus minimizing chafe. You do however want to have a smooth lip or toe rail edge and or stainless half rounds to protect the gelcoat.
3) Swivels are the weak link and should be considerably over-sized. I use a 1" swivel on a 36 footer and it is replaced ever four or five years or sooner depending on wear. The best location for them is directly under the ball where you are placing it as it can more easily be inspected.
4) Be sure your 12' of pendant is enough. You do not want a sharp angle off the bow. Sharp angles cause more wear & tear than long low angles.
Even with the bow high in the air you still don't want a very steep angle.
Too Short for a harbor with any exposure:
5) Have you considered Yale Polydyne pendants? They are amazingly tough, abrasion resistant and stretchy. In Falmouth they survive storms far better than three strand. Even with both having chafe protection. Mine have survived a number of Nor'Easters with no issues, including this one.
Nor' Easter Video
6) As for the connection to the swivel I use an over-sized CM load rated shackle. The pendants are then laces together with floats to keep them in the same orientation. The trick is to put one very close to the shackle to keep the pendants in tension against the underside of the ball so that can't droop, kink & tangle.
Two Yale Polydyne Pendants, one shackle:
7) Un-equal length pendants are a safer choice. With two equal length pendants you can have nearly equal wear. With one pendant longer than the other as a secondary or back up pendant it becomes the perfectly brand new pendant when the primary use pendant fails. Some boat will sail at anchor no matter what you do. My mooring guy services over 1000 moorings and uses un-equal length pendants. The have not lost a boat in years..
8) Lace on some floats to prevent ball tangles. Also if you have an anchor make sure it can not interfere with the pendants.
9) Bow eyes can be a decent option IF and only IF it is robust enough in design. It can avoid chafe issues and pendant angle issues. Sadly though most are not designed or robust enough for shock loading. My neighbor pulled one out of a small O'Day..