Taxability of windmill sale

In our compnay we have 6 windmill and we are claiming deduction ( profit of windmills) unit u/s 80IA. In current year we are planning to sale one windmill

My Query is

1. Profit of sales of the said depreciable asset will be treated as Short Term Capital Gain u/s 50 (WDV is zero as per IT ACT)
2. We have to pay STCG Tax   @ 15% + applicable cess
3. We have MAT credit balance and brought forward short term capital loss. Can we adjust the said remaining (after setoff the STCL) liability against MAT credit or have to pay cash.
4. Can we continue to claim profit of windmill unit u/s 80IA for remaining 5 windmills?