If you get enough water in the tank, you will get separation with E10. Regardless of E10 or not, excess water in the tank will be an issue.
Note that when drygas is added to non ethanol gas as many folks did in the past, it posed the same potential issues with respect to hoses and suck that didn't like alcohol compounds. As I have said many times before, E10 gas cab tolerate a little water better than non-e10 since it absorbs about 1/2% by volume.
Most if not all of the boats I see with water in the fuel issues are due to either water intrusion into the tank, usually from a defective filler cap or vent, or a bad load of fuel. I am seeing more of that after Sandy. It appears that some fuel stations that were flooded got water in their tanks.
Yes I have seen boats with decaying/internally collapsing fuel lines but all of those were pretty old hoses.
I also hear often about breakdowns that occur after a good intentioned boater adds a 'lot' of fuel additives especially to decarb. In many cases, the motor ran fine before the process. Loosening up a lot of gunk at one time can cause major problems to fuel components. There is no substitute for fresh gas. If you are not going to use a full tank, don't fill. I try to add new gas to cover my next two trips. My tank is rarely more than half full at the start of an outing ( Yes I have plenty of gas for my planned outing).
That also saves fuel since I am not hauling the extra weight.