He can hide all kinds of things without it making him ineligible for the office. Remember, the issue is legal eligibility, not his character.
Also, he hasn't spent millions to hide things. He's spent whatever to pay lawyers to write filings in lawsuits he didn't originate. They've done exactly what they should be expected to do in the circumstances.
What was the intent of those filings, if not to keep things hidden? For example EX PARTE APPLICATION FOR LIMITED STAY OF DISCOVERY or their Motion for Dismissal
The former actively sought, successfully to continue to hide information. The latter, is all about standing, jurisdiction and other "technical" issues, not defending Obama as in "He is so eligible".