[Antennas] 80m Horiz Loop - confirm configuration

[k1drw]

I will be installing an 80m horizontal loop approx 35 high.  I will be
feeding the loop using approx 100 feet of 450 ohm window ladderline
to the eve of my house.   Then, drip loop to under the eve where it will
connect to a Current balun, then 9913F coax (approx 30 feet) down the
side of the house (drip loop again) to an SPG enclosure (Single Point Ground
connected to a ground bar system) connecting to a Cushcraft
LAC4H lightning protector mounted on the SPG.  Then, into the shack using a
9913F coax jumper approx 10 feet long, to the tuner.  The loop will be used
with 100w across 10m - 160m bands for both local and DX contacts.
Questions:  1. Should the total feedline length, or any part of it, be
optimized to any length (1/2 wave), or not...?
 2. The loop will be square with 68 feet per side (272 feet total).  I have
room to increase the antenna length, making it more rectangular with 2 sides
of approx 100 feet and non resonant .  Should I....??
3.  I will be using Dacron double braided poly line to support the loop.  Is
3/32 dia rope strong enough or should I use 3/16 dia rope.
Any advice will be sincerely appreciated.  Dennis, K1DRW, Philadelphia area.