<<The flex line comes very close to the exhaust pipe.... could a person use a solid line from the fuel pump to the fuel servo, similar to the solid line from the prop gov. to the front of the engine?>>
Jonathan, I assume the servo is a Bendix. Route a firesleeved flex line along the port side
above the wing on the sump, much like the hard oil line runs along the starboard side. A 45 fitting on the end of the line will couple to the port side of the servo well clear of the mixture arm. You can secure the line front and rear with two adels on the 1/4" sump bolts. If you need to run wiring in the same area, attach a mounting plate to the sump bolts and space the fuel line and wiring well apart and parallel using adels on the plate.
<<I had initial concers also but I found that by holding the line away from the exhaust while tightening the servo fitting, the line tightened up and is held away from the hot parts. >>
Jekyll, dependence on flare fitting friction might not be a good idea.