Wasn't the balanced budget and the surplus of the late 90s mostly due to the economic boom ?
No again Clinton said it couldnt be done. It was a direct result of te republicans budget.

Don't forget that the republican wanted tax cuts, if they had passed the US would have run an even larger deficit after the .com stockmarket crash.
This has been proven false once again. Reducing taxes actually increases federal tax income. You get a smaller piece but of a much bigger pie.

I really don't understand why Bush is handing out tax cuts to individuals when the budget is far from balanced and you are running a record deficit, why does Congress (and the Republicans in it) approve this ?
Again it stimulates the economy and actually increases revenue.