Man, this mailing list seems to love my contaminative presence. If you
don't want me to post please don't challenge my previous postings.
Otherwise, I'll have to respond.

1. "As-Salam" is a noun, "Salam," with the definite article "Al." It means
"peace." It is also one of the many descriptive names of Allah.

2. The two classes of letters you refer to are called "Shamsii" and
"Qamarii" (with stressed "i"). Meaning "solar" and "lunar," respectively.
The "solar" consonants are the Arabic equivalents of "sh," "n," "l," "z"
(all four Arabic consonants that sound like /z/ to you, i.e. "ذ", "ض",
"ظ", and "ز"), "r," "d," "s," (the three /s/ sounding consonants, i.e.
"ث", "ص", and "س"), "t" (both /t/ sounding ones, i.e. "ت" and "ط").
The rest of consonants are "lunar."

3. "Salam-on alaikom," transliteration of "سلام علیکم," is a
greeting. It is not some sort of mantra directed at Allah. It means "peace
be upon you." And it isn't reserved for Muslims. In any sane
Arabic-speaking country--and some non-Arabic-speaking countries--you'll be
greeted by that same phrase. The phrase corresponds exactly to the famous
Hebrew "Shalom aleichem," which also means "peace be upon you."