Ltd Contractor: Compare Company Car to Commercial

[Lethal83]

I am a one man Ltd company. I work as an engineering contractor and only work for one company.

Upto now I have been using my personal car and claiming expenses out of the company.

I want to investigate buying a company car versus a commercial vehicle.

A company car attracts BIK which appears relatively straight forward linked to the Original Open Market Value and Annual Businees Km.
Q1: Can you claim the VAT back on the purchase of car?
Q2: Can you claim the VAT back on the diesel?
Q3: Can you claim the VAT back on maintenance?
Q4: If the company pays the Road tax, Insurance, fuel and maintenance is this value then subject to BIK?
Q5:Can you claim capital allowances on the purchase. If so is this reduced due to personal use?

A commercail Vehicle;
Q1: Can you claim the VAT back on the purchase of vehicle?
Q2: Can you claim the VAT back on the diesel?
Q3: Can you claim the VAT back on maintenance?
Q4: If the company pays the Road tax, Insurance, fuel and maintenance is this value then subject to BIK?
Q5: Is it accurate to say that the BIK on commercial vehicle is 5% across the board?
Q6:Can you claim capital allowances on the purchase. If so is this reduced due to personal use?

Please add to this or give your experiences.