In the United States, the states outline procedures for being legally married. It varies slightly from state to state, but perhaps the single key step is that one must register a marriage agreement at the local courthouse for it to be considered valid.
That is, you and your spouse must fill in a legal marriage certificate, and have it witnessed (and countersigned) by a legally valid person (usually a notary public, government official, or officially recognized marriage performer, aka a religious minister).
In short, there are official documents that must be physically signed and witnessed before a marriage can be legal. Simply saying "we're married" isn't valid. Which is what "marriage by cell phone" boils down to.
No, it isn't legal to bug cell phones or jam them.
No
no
It is legal to use on your kid or employee or on a phone you own
Yes, that is perfectly legal.
yes
Yes.
If you are the legal owner, you can get copies of call logs and locations where calls were made from the cell phone service provider.
If it is legal for schools to keep a cell phone for 9 weeks would depend upon what their code of conduct rules say. Most schools will not keep a phone for this long.
Laws vary from area to area, but in general, it is legal to law enforcement officers to search a cell phone if it is believed that the cell phone contains information pertaining to the arrest. To give a specific answer, the geographic area will need to be provided.
yes
An online marriage isn't legal in either country. An embassy would have to be involved.