I can't tell if these close with just the velcro in the front?
Yes, they velcro from top to bottom so you wrap the gaiter around your boots. They also have a hook on the bottom front to attach them to your laces to keep them in place. A strap around the top also keeps them snug. I hope this helps.
Yes, velcro up the front. There's a strap closure at the top as well.
Yes just wide velcro, plus a webbing strap with metal clip at top. They have never come open on me.
Yes, there is a velcro strip that runs the entire front. Very good quality.