This would depend on why you were arrested and if the cellphone is evidence of the crime(s) you may have committed.
As for never giving it back, that would be an issue of civil asset forfeiture, which brings to light a whole slew of constitutional issues that have been rarely addressed yet.
My suggestion would be to file a motion with the court seeking return of your property. The prosecutor and police will have to file a response to the motion explaining why they need to keep it and approximately how long it's use is needed. If the Judge hearing the motion feels there is not a legitimate need for the Police to keep it, they will have it returned.
Lastly, Police need a warrant to go through the phone, even after arrest. It's been ruled that cellphones are to be treated as an extension of the body and requires a warrant to be looked through.
yes
Anything they find from you regarding a crime.
It means to sieze or to take into custody.
yes they do check you. Typically, as part of the arrest process, there is a search. However, depending upon the circumstances, the search may take place before the arrest, or you may be under arrest and the search can take place after.
take it to the pound or animal shelter
No, the Warrant gives the Police the authority to take your liberty, it is not negotiable.
The police can arrest you ANYWHERE.
an arrest warrant.
no, you can not. but police can arrest you.
In most cases the officer will inform you of the reason for your arrest and take you in to custody for booking. You may or may not be advised of your Miranda Rights at arrest but should be advised before your are questioned after arrest.
You could try a citizen's arrest but the police man may refuse to be arrested. It is only a warranted police officer that is empowered by society to forcibly arrest someone.
You apprehend the person in question and, restrain them and then call the police and they will take control from there.
I wouldn't do it. They might take it TOO seriously, and arrest you.