Bound Root?

This afternoon I and my students (in NTPU) had a sharp argue over what a bound root truely is.

Here's the source of trouble: a root may or may NOT stand alone.

According to what i know about a root, it should be something that can be the base of a morphologically complex word. Since it is called as a root, it usually carries the core meaning of a word. Sometimes, the root is a word itself if there is no other constituent (like an affix or a free morpheme) attached to it. In this sense, a root is equal to a word.

Then, what is a BOUND root?

A bound root is a bound morpheme which acts more like as a root than an affix. However, unlike the free roots, the bound roots have no meaning in isolation. They can only be attached to specific morpheme to acquire meaning. For example, the word lukewarm is composed of two roots --- one is the word warm, the other is a bound root luke. Other than lukewarm, we can hardly find any word made up with luke. (One thing to be set clear here is, it is not the same word as the name Luke)

The same situation can be found in the morphological structure of huckleberry and boysenberry.

Other than this type of morpheme, we have an even tough one.

Some bound roots do occur in many words, but they don't seem to have a consistant meaning.
per-ceive
re-ceive
con-ceive
de-ceive

If ceive in these cases is counted as a bound root, what should we do with vise in the following words?

advise
revise
previse

And if the word televise can be divided into tele and vise, a prefix and a (free) root, then in what way may we analyze the above examples? Two different morphemes(free and bound) in the same form? Getting to the heart of the matter, if a morpheme is a root, then it is always a root. If it is not, it will never be in any case, not even in the name of BOUND. Agree?