A few comments, none of which are legal advice, talk to your attorney, this is all academic based on things I’ve read and been told and not applicable to real life:

1) The holding period cannot be simply summarized nationwide. For example, by statute, in Massachusetts I believe you have to be arraigned within 24 hours unless there are extraordinary circumstances, or you waive the right. I believe Police questioning must be complete within 6 hours of arrest again, unless you waive the right. I encourage someone to check the state statute on that
2) Again this is all based on my understanding and is not legal advice, exercising your Fifth Amendment right to silence cannot be used as evidence against you. Where you may find yourself in trouble is if you give an incomplete or inaccurate story and swear to it.
3) You should do whatever your attorney tells you, but if I’m ever handcuffed for any reason or I have my freedom of movement restricted, regardless of whether or not I’m told I’m under arrest I’ll consider myself under arrest and I’ll request council immediately. I will not answer any questions regardless of benign they may or may not seem, without my council present.
4) People may have heard of situations where police can, say, question without reading Miranda rights and obtaining a waiver and evidence still comes in. These situations may exist, for example, physical evidence found as a result of a bad interrogation or “fruit of a poisonous tree” will likely be admitted, as will evidence obtained in questioning when public safety is a concern.
5) By “hostile witness” I mean one that is not cooperative. Generally this means the other side’s witness. Say you’re a prosecutor, when you cross examine the defense’s witness they’re likely to be hostile. That said, as defense council you might call a police officer to the stand that the prosecution did not who may go against your cause, as far as I understand it, that person may be a “hostile witness” as they may not give cooperative answers to questions.

Most importantly, remember talk to your attorney, this is all academic based on things I’ve read and been told and not applicable to real life. I am not an attorney; this post merely reflects how I intend to handle myself in a police interaction, not because I don’t want to be helpful but because it is how I understand police/citizen interactions to work. You should seek legal council to determine how you might interact with law enforcement in a situation.