Bonus Depreciation question

I bought a small commercial building for $199,000 in 2003. I built a new building shell completed in December of 2006 at a cost of $600,000. In 2011, I built the inside with Tenant improvements at a cost 0f $60,000. On August 1, 2011, I put the building in service and rented it. I think I qualify for the bonus depreciation on $60,000 Tenant Improvements which means I can take the deduction in one year

2011. First what if I have more depreciation in 2011 than income? Second question do I calculate also my depreciation on building shell over 39 years. TurboTax asked me for cost of asset when acquired and the cost of the improvements but not the cost of building the shell on the Asset Worksheet.