Yes, I believe there is only one God. Now, tell me how the word ECHAD denies the clear, obvious, eternal relational distinction between the Father, Son and Spirit that all share the one name, YHWH. (cf John 14:16-17, 26; Matt 28:19).
sure, the ECHAD is in Ordinal Designation. example, Deuteronomy 6:4 "Hear, O Israel: The LORD our God is one LORD:"
ONE .... "LORD" using the Mickelson's Enhanced Strong's Dictionaries of the Greek and Hebrew Testaments, "ONE" is the Hebrew term, H259 אֶחָד 'echad (ech-awd') adj.
1. (properly) united, i.e. one.
2. (as an ordinal) first.
[a numeral from H258]
KJV: a, alike, alone, altogether, and, any(-thing), apiece, a certain, (dai-)ly, each (one), + eleven, every, few, first, + highway, a man, once, one, only, other, some, together.
Note definition#2. Ordinal "FIRST". as the ECHAD of himself, he's the FIRST and the LAST. let's see it in scriptures. Isaiah 41:4 "Who hath wrought and done it, calling the generations from the beginning? I the LORD, the first, and with the last; I am he." the Lord is "WITH" the Last... correct. just as in John 1:1 the Word was ... "WITH" .... God correct. now this, Isaiah 48:12 "Hearken unto me, O Jacob and Israel, my called; I am he; I am the first, I also am the last."
did you get that? if not, the LORD is the FIRST and the LAST, the SAME one person. for ALSO means, "in addition; too". same one person, ANOTHER. of himself. which proves 101G point about the LORD and the "Lord" in Palms 110:1 and 5 the same one person, only diversified in flesh, hence the Empathic form of "Lord" in Psalms 110:1 and 5.
now to your other question,