Well clearly your business credit card apps keep getting declined because of too many inquiries so don't take any hard pulls for a while. Read and follow the steps in the business credit 101 thread. It will help you start building business credit all while keeping you from taking hard pulls.
Most credit card applications will result in a hard pull regardless of your business credit (exceptions like Sam's club or amex once you're already in) so they can usually be applied for at any point in the business credit building process (depending on the strength of the individuals credit of course), but hard pulls are hurting your approval odds, so my suggestion is you wait on credit card apps and build your business credit. In 6-12 months the "too many inquiries" issue will be less of a problem so your business cc apps will be getting approved and you'll have established a solid enough business credit foundation to the point where you'll be able to be approved for better business credit accounts without providing a PG and not having to take those unecessary hard pulls.