One of the basic student eligibility requirements for a student to receive financial aid is that s/he not be in default on a Federal student loan. As long as you don't have a defaulted Federal...
Yes, you just have to be in good standing. Not delinquent. If you are delinquent, there are options such as forbearance and deferments for bringing you current so you can get more loans.
The lender can, at their option, immediately demand payment in full. Failure to pay that may find yourself in a courtroom being sued for the full amount and any other damages. Read the fine print in...