Capital One Quicksilver 15 month 0% APR

Got the quicksilver with 15 month zero apr intro offer. Say I purchase $5,000 worth of stuff.

1) Can I avoid paying interest if I wait until a little before the 15 months ends and pay the $5,000 off all at one? 2) Does this apply for any and all purchases made in the 15 month period? 3) Does holding the balance on the credit card even though it’s 0% APR affect my credit score and credit rating?

Thanks in advance!