Querying with VCF Tools

[nkline]

Hello. I have some VCF files which I will be working with. Today I came across a tool named VCF Tools and it seems like it might be useful. However, before I download and install it, I was wondering if it will be able to answer all of the following case scenarios or should I build my own program to parse my files?

Case Scenario 1:

All known (have an RS id) polymorphic positions for sample IDs starting with P0048* with AF<0.10.

Case Scenario 2:

All unknown polymorphic positions for sample IDs starting with P0048* with AF<0.10.

Case Scenario 3:

All known (have an RS id) polymorphic positions for sample IDs starting with P0048* with AF<0.10. Report the genotypes for all individuals in the family that have a coverage for those positions greater than 20 (i.e. DP >20) for individuals with DP <20 replace genotype with ./.

Thanks!