Leave to you to Suzanne to ask thought provoking questions!!
1. Gold is often used in the bible to illustrate that which is eternal. No matter how many times it becomes polluted you can always put it through the fire and purify it. The gold Jesus was talking about was that which is eternal. Silver is temporary and always eludes to something of temporary value. Thus, Jesus was betrayed for silver, something of temporary value.
Gold however is a metal that never loses its value. It's value is eternal. The salvation through Jesus Christ is the gold He is speaking of to the Laodiceans. Salvation through Jesus Christ, like gold, has eternal value.
Because you say, 'I am rich, have become wealthy..
We must understand that Laodicea or "Peoples Opinions" will always betray Jesus for something of temporary value. Something this world has to offer of temporary value. Wealth is something of temporary value. It is the silver that betrayed Jesus then and will continue to betray Him until the Last Day.
2. This is partially covered by the previous answer. Let's look at scripture.
For You have tried us, O God; You have refined us as silver is refined. Psalm 66:10
It's clear and simple. Refining the gold is just what God is doing in the life of one who is born again. You refine gold because the finished product has everlasting or eternal value. This is all illustrative of the things which have already been said in plain and simple language.
"Behold, I have refined you, but not as silver; I have tested you in the furnace of affliction. Isaiah 48:10
6 "Your dwelling is in the midst of deceit; Through deceit they refuse to know Me," declares the LORD.
7 Therefore thus says the LORD of hosts, "Behold, I will refine them and assay them; For what else can I do, because of the daughter of My people? Jeremiah 9:6-7
"Some of those who have insight will fall, in order to refine, purge and make them pure until the end time; because it is still to come at the appointed time. Daniel 11:35
"And I will bring the third part through the fire, Refine them as silver is refined, And test them as gold is tested. They will call on My name,And I will answer them; I will say, 'They are My people, 'And they will say, 'The LORD is my God.'" Zechariah 13:9
"But who can endure the day of His coming? And who can stand when He appears? For He is like a refiner's fire and like fullers' soap. Malachi 3:2
..and it goes on and on until the gold is pure.
3. Again! The reference is to the garments of salvation in Isaiah. It is not that the Laodiceans weren't saved but that they had taken off the garments of their salvation. Salvation is not lost but is rejected or trampled under foot according to Hebrews 10 by some Christians. This is the peril of falling away.
I will rejoice greatly in the LORD,My soul will exult in my God; For He has clothed me with garments of salvation, He has wrapped me with a robe of righteousness, As a bridegroom decks himself with a garland,And as a bride adorns herself with her jewels. Isaiah 61:10
4. Eye salve so you may see?
Because of the backslidden condition of Laodicea they are unable to understand the scriptures. Remember the foolish virgins? They needed oil in their lamps to see in the coming darkness of the night. The night is something often used in scripture to typify the Great Tribulation - the Time of Jacob's Trouble. Different liquids typify the Holy Spirit in the different aspects of His ministry such as water, oil, wine, etc. In this case Jesus is using something that was well known in that day as a remedy for the eyes. Remember each church was threatened to repent or have the lampstand removed which is yet another reference to the presence of the Holy Spirit.
I'm pressed for time or I'd further expound the subject. This is most enjoyable... I need to get out of the debates and join the bible studies.