eamon
Explorer
If DM is considering house ruling it so that one can take the utility swap feat more than once, one thing to keep in mind is that some utilities can be a lot more powerful if available to a different class.
For example, in my group we have a tactical warlord who has multiclassed into wizard. For his utility swap power he took Fire Shield, which basically means that for one encounter per day, any enemy that hits him with a melee attack takes a decent amount of fire damage.
That particular utility is quite a lot more powerful for a melee character than a wizard... and I imagine there are other utilities that are also more powerful if taken by a different class.
Sure, but each time you do so it's costing a feat slot and another power. There's almost always another decent feat around, so this isn't generally going to be a great option power-wise; and since you're in custom rules territory, the DM should be looking over the shoulder to spot any particularly wonky interactions. And each additional power-swap feat is going to be worth less, typically - after all, you did pick the most attractive choice to swap out the first time.
If people invest all that effort into their character, that's just another hook for the DM... I'm not too worried about this particular issue. It's outside of the core rules so you should be wary of odd interactions, but straightforward power issues seem very unlikely.