Trust is a big deal especially for senior positions

Perhaps I should explain more why it is a dangerous idea to re-negotiate base salary. Especially for senior positions, they are not only evaluating your capability, they are also evaluating your character, including trustworthiness. If you give them doubt about your character, there is no going back for a lower salary. They just disqualify you.

Companies typically interview what they can afford for senior positions. The HR guy has the job to screen candidates and see if they meet the affordability requirements. If you change your expectation and become outside the range, the HR guy will be criticized for wasting people's time to interview this candidate, and you certainly do not make friends there.

The easiest part to negotiate is signing bonus. Companies do not need to worry about employees compare their salaries and complain, so they are more willing to negotiate. People at senior positions often have a large amount of stocks or options they will lose when leaving the prior company, so they need more room to negotiate signing bonus to make up the difference.

By the way, anyone having a diva screen name should be prepared for some (friendly) teasing ... according to the US culture:-)