==> Is there a word for generational name suffixes?
Not to my knowledge. Just as you have, I've always heard them called to 'generational suffixes'.
==> Is there a word for educational name suffixes such as M.D., R.N., or Ph.D?
They could be called degrees, certifications, accreditations, titles, or salutations (rare) depending of what they represent. These terms are not necessarily synonymous as each has its own individual meaning, so they are not inter-changeable. You might refer to the entire group generically as 'credentials'.
An honorific is a title bestowed on a person because of an earned credential. For example, a medical professional who has an M.D. (degree) may have referred to as Doctor (honorific). A university teacher who has a Ph.D. (degree) may be referred to as Professor (honorific).
Good Luck
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