Question One: Use what you want here
Use will or would here at your discretion; both are acceptable. Using "will" will give your sentence more power, it is a stronger statement of truth. "Would" is more open ended and gentle.
Question Two: Yes, wh-clause
Yes. "which kind of products I'm talking about" is replacing a noun in the sentence. It is classified as a wh-clause since is starts with a "wh" word.
A subordinate clause that is introduced by one of the wh-words (what, who, which, when, where, why, how).
Wh-clauses can function as subjects, objects, or complements.
"An important aspect of wh-clauses," notes Geoffrey Leech, "is that they require the wh-element to be placed at the beginning of the clause, even if this means changing the normal order of subject, verb, object and so on" (A Glossary of English Grammar, 2010). See Examples and Observations, below.
I would like to suggest that "which" change to "what". "Which" is best used when there is a discrete list of items. "What" is best when you could be talking about anything.
"No one will understand what kinds of products I'm talking about."