Deduction will always have to be a part of the equation. Otherwise some business could not exist. For some corporations profits are not realized for years. Others operate on very seasonal basis. But simplification is necessary.
YES, as per my suggestion above. Tax codes typically arise because some genius politician has an idea on how to "incentivize" a corporations, or individuals actions.
Human behavior as its always worked. In sports, taxation, life, etc. writing on the wall is interpreted in different ways.
The statutes around taxation need to be more agile. So unintended consequences can be quickly addressed. The code simplified. To raise more money the slope of the marginal rate increased. More enforcement is needed.
The US is 1/2 way between Greece and the Nordic countries. Concerning outright cheating and the citizens who think the tax systems are fair and just.
As a part of this equation is the entire idea that government supplies needed services. That government is efficient. When government is painted as "evil" and "enemy", a swamp of waste, corruption, etc. Its citizens are more likely to cheat and go to extreme lengths to avoid paying taxes.