not recommended
Yes.
Reuse is a verb (to use something again) and a noun (in a state of reuse).
yes
no, you have to replace them every time
I would not recommend it. The bolts are stretched during the torque procedure.
Use again
to use again and again
reuse
Yes, if they are not damaged in any way.
because you can reuse them when you plant seeds you get more seeds that you can reuse over and over again
things that can be reused again
You can, but I would advise against it. The old bolts have streatched and you should install new head bolts.