Keep previous licenses?

I think you should renew. Always.

I renew my pharmacy technician license always, even though I don't plan on using it again.

My father was a pharmacist, worked in corporate as a buyer for a grocery store for 20+ years, let his license lapse, and now that the economy tanked, he has to go through extra to reinstate it to work as a pharmacist again.

My mother retired, kept her pharmacy license up to date, and when she went back into the workforce 4 years later, she could accept a job immediately.

You never know. If you don't renew, will you regret it later?

I wouldn't bother with the CNA certification. Even if you wanted to apply for a job as a CNA, your RN license already gives you the qualifications that you need to fill that position, and most states don't let a licensed RN work as a CNA anyway.

The phlebotomy certification might be worth keeping up. You might decide down the road that you want to supplement your income or take a phlebotomy position as a change of pace. It also gives you a nice leg up when applying for nursing jobs.

you know, it may be expensive to renew but it's always a good thing to have them available to you (just my two cents) in case something happens and you do have at least something to fall back on. (: