I know people that ride with the boots almost open. The basically jump in and then just make sure the laces don't flop around and tie them. I couldn't ride like that.
Too tight is very easily achieved. I remember my Northwave boots from 1997, I really had to crank those down hard to get them supportive. With todays boots I just gently pull on the laces and thats it. If you think its not tight enough you might want a smaller boot, or one with less flex.