I like the name [name]Bennett[/name]. It’s in my top 10, but not one of the four I’m really considering. And it is only because I’m afraid if he goes by [name]Ben[/name] or we call him [name]Ben[/name] that people will assume his name is [name]Benjamin[/name]. Is that a realistic concern?
I don’t think it’s a serious concern. If people assume his name is [name]Benjamin[/name], they might be interested and excited to hear his name is really [name]Bennett[/name].
I don’t think so. If you love [name]Bennett[/name], I would use it! The meaning of “blessed” is wonderful, and I would just make sure I called him [name]Bennett[/name] enough that people would understand that he’s a [name]Bennett[/name], not a [name]Benjamin[/name]. 
I had a boyfriend whose name was [name]Wilson[/name], and he went by [name]Wil[/name]. Occasionally, people would call him [name]William[/name]. It was a simple enough thing to correct them, although I didn’t date him long enough to know if he found it annoying.