With most companies, the issue is that the person you are dealing with is
not someone you will have a relationship with. It will not be your new manager. It will be someone from HR. They'll have a salary range, and will be willing to move to near the top depending on how much the hiring manager says how good you are. At an individual level, they don't care if you "trust" them.
If you're asking for something beyond their upper bound, they'll have a few other levers to offer you (more stock, one time sign on bonus, etc). But keep in mind: If the manager said you were "good, but not great", they're not going to go much higher than their initial offer to you.
In all these scenarios, they have zero incentive to discuss how they came up with that number. If you indicate you can't trust them if they don't, they'll agree and drop you and look for another candidate. The HR person is dealing with multiple hires for multiple positions. He/she doesn't have the time to do a detailed discussion with every one. What's more, what is the point of them sharing it? Put yourself in their shoes. They've come up with a compensation strategy for the whole company. If they're offering below market and they know it, your pointing it out to them doesn't strengthen your position. They know the information your providing them. If they were trying to save money, they'll increase the offer. If their policy is to underpay, they're not going to raise the offer unless the hiring manager indicated you're well above average.
> and apply the right amounts of awkward silence.
Silence is awesome for certain scenarios, but not when dealing with an HR person on a compensation package. Remember: Your asking a question (like the one in your comment) does not throw the ball in their court. They'll either ignore you or give you a canned response. Every offer has a deadline, and they'll ping you again near the deadline. If you continue the silence, they'll withdraw the offer and move on.
If you're joining a small company/startup, your tactics will work. Not so with established companies.
There are stories here on HN about people who had been hired, but were not happy with some of the paperwork they were being asked to sign on their first day on the job. They stood their ground and that was their last day at work. If a company is willing to do that after they've gone through the headache of hiring a person, then don't assume that you have any decent leverage with notions of "it's too painful for them to withdraw an offer and hire another person - they'd rather negotiate."