Yes this is what I had to purchase to put around my water heater and secure the water heater to the wall. I did that myself in a home I was selling and noticed that the plumbers that were setting the water heater in my new home also did that for it to pass inspection. Check with you building department and they will make sure you know how it is done.
Yes. Drilled holes throughout the length of the strap making it easily adjustable.
If it's blocked and strapped correctly, yes, but I'd still have help if it's really stuck.
Yes, especially if you ever want to sell your home. Appraisers here in Washington State call for it to be done.
It contains 4 pieces that create 2 straps. Be sure you have a socket set. The direction on the package are good and will note tools also.
This depends on the State you live in. It is required by code in California. In a severe earthquake, my opinion is a closet may not contain or hold a water heater in place. Apart from water damage if the water heater moves, a damaged gas line ( if a gas heater ), is another cause for concern. My home owner insurance in California made strapping the water heater regardless of where it is installed, requirement. I now live in Texas and i wanted to have the same sense of security, although not required by code here, but i live in a Tornado prone area.
In most city's yes.
Yes! just cut the strap, or let it hang long.
They can be cut shorter if need be.