Yes, you are correct. Student loan interest is tax deductible as an adjustment to your income up to $2500 per year. If you have the means of paying the interest during the forebearance period, then that is the way to go. Otherwise the interest gets capitalized and you will start paying interest on the interest. Once you see what your income will look like, I suggest snowballing your student loans starting with the lowest balance one. This will allow you to start decreasing the number of student loans that you have gradually, and when they come up for repayment again in a year, you will have less student loans, so a lower monthly commitment that is required to put toward your student loans.
Yes. If you have not consolidated your loans and are paying through the servicer's website, you can typically chose which loan you want your payment to go toward.
It's not a dollar for dollar refund on the interest. A percertage of the student loan interest your pay is deducted from your income, thus decreasing the income that you have to pay taxes on. So paying $2500 in student loan interest does not equate to a $2500 tax refund. I am not a CPA, and I hate tax law, but the below is a calculator on the IRS website you can use to do some estimates. https://www.irs.gov/uac/can-i-claim-a-deduction-for-student-loan-interest