Be certain that any hose you use is 'E85' compatable and that the one that goes inside the tank can be submerged in fuel.
That soft hose you mentioned would likely collapse with suction from the pump. As for the venting, if you don't have any, a new pump and hoses won't do any good. These emissions systems are closed/sealed so, if there is no venting in you won't get anything (gas) out.
Check from the charcoal canister to the tank. There is a valve in the top of the cannister that may have stuck. Other things to check would be pinched return lines/hoses. The filter at the bottom of the canister is rarely an issue but I wouldn't leave it unchecked.
Since you have the tank off and an air compressor handy, 90 PSI should find the problem!
Even if the pump looks new it could be bad. Figure in how many miles on the engine to estimated MPG and you start to get an idea of how many gallons that little thing has pumped. A bench test will answer this but be mindful of any sparks that would cause an even bigger problem.