This is largely correct, if a bit of excessive hyperbole. The richer you are the higher the likelihood that you can and will take advantage of loopholes or shelters. The tax code needs to be simplified and the number of deductions and eligibility for those slashed. There has been rumblings from both parties about this but nothing ever gets done.
The rich are very likely to take their money out of the country, if their taxes are too high.
This is true, however, current rates on the highest earners are at historically low levels and you still have money fleeing to the Caymans or whatever the flavor haven of the month is. You really need to get better on the enforcement and collection side of things. I think a small step toward this is to simplify the code.