Exemption under Section 54 for LTCG

kindly help me in clarifying my doubts about exemption 54:

1. does it apply for vacant plot of land? agricultural land?

2. can you sell 5 properties for example to avail exemption upto 2 crores?

3. can reinvest in maximum 2 new properties? if you already have 5 properties, what happens?

4. you have property A for 5 years. you gift it to a family member and they immediately sell it. can they avail exemption 54 on sale of property A?

thank you.