For tax purpose is better to have separate accounts, business and personal and pay all business expenses with the corporate account, also when you put money into you business you should write that amount of money as a loan, accountably speaking, because when you start making money you can paid the money back from that gains so in this way you don`t have to pay taxes for all your gains. if your are the still is good idea to have different accounts.
if you need a credit in your corporation name, you can build asking the credit card issuer to have the name of the company in the records, if you need to buy equipment buy it in the name of the corporation, some stores can give the credit in your corporation name. just to give some ideas.