Actually, I like that Arc overloads so many things. I suspect the primary reason I dislike using . for functions is because of my JavaScript background. After years of programming in JavaScript, it's become very ingrained into me that . means "property access"
I agree that for my code it's a simple matter of not using the syntax in the areas that I don't like it. In fact, I don't need to use any syntax at all: I could use pure S-expressions if I wanted.
I guess what it comes down to is, "I want to use . for property access in tables, or at least use something that's not !" and although it looks weird to me to use . for function calls, I'll concede that Arc is not JavaScript, so I think I can tolerate it.
Thus, combining . and ! might be the best way. Alternatively, I think these would be very nice as well: