Ick, hyposalinity, and other mistakes...

[Scuba Diver Gal]

Hello,

Needing some advice. This is my son's tank but I help him with it as we are both new to the hobby. We have a 29 gallon biocube that has been running for approximately 2 months. Here is what has happened:

- had 2 tank bred young clowns in the tank
- added one purple fire fish and some corals (GSP, torch, etc.)
- things in the tank were going along swimmingly
- this week went to LFS and my son was assured that he could put a Dwarf Angel in the tank also recommended a yellow tang. I didn't think it was right but in the end the person at the store seemed very confident the dwarf angel would be fine
- put the Flame Angel fish into the tank (didn't quarantine, I know, I know…we now have a quarantine tank running) (being new it's overwhelming enough to get a simple AIO tank let alone make a quarantine tank…
- within 12 hours the Dwarf Angel had white spots…one that went away, then another one showed up a few hours later, then gone completely, then a few more, etc, etc.
- 2 days later we removed the Dwarf Angel from the tank and took it back to the LFS - we were told it was not ick from the Dwarf Angel etc, etc.
- I don't really care at this point what caused the ick, all we cared about was he wouldn't destroy the fish and would treat it and now WHAT DO WE DO???

HERE IS WHAT ADVICE WE HAVE BEEN GIVEN FROM A VERY RELIABLE SOURCE (only doubting because some people have told us other things that scare us from jumping into what the reliable source tells us to do).
- quarantine the 2 clowns and purple fire fish (all 3 of these fish look PERFECTLY healthy right now and are acting completely normal) in hypo salinit for 8 weeks
- let tank sit fallow for 8 weeks to let all ick in the tank die
- slowly return the 3 fish to regular salinity and then return them to the main tank

HERE IS WHAT WE HAVE BEEN TOLD BY OTHER SOMEWHAT RELIABLE SOURCES:
- purple fire fish will die within 2 days in hypo salinity
- there is ick in every tank even if we let it sit fallow and it needs to sit for at least 12 weeks and still can have ick
- don't do anything if the 3 fish aren't showing any signs of ick
- putting them in quarantine will stress them too much and cause them to become sick too
- don't worry about the ick at all, we may never see signs of it again now that the Dwarf Angel is gone
- flush all 3 fish and give up on raising fish at all
- don't medicate with copper etc because we are beginners

HERE ARE OUR CONSIDERATIONS:
- seriously considering to upgrade to a new bigger tank in the next 6 months and would like to use existing live rock, fish, and corals (won't keep sand)
- only want to add 1-2 more fish to the tank anyways
- are we CRAZY for even considering getting a LARGER TANK???!!!??? especially after all these trips to and from the fish stores this week???
- we really don't want to harm these fish and make this as easy on them as possible
- don't want to move ick into our next tank

Sorry for the long post but we are just lost. We trust our first person but all these other bits of advice have totally scared us, so we have really done nothing…

Do any of you have experience with this and considering what we are planning for future upgrade, what would you do?

Please, we were already shamed yesterday by someone over the Dwarf Angel, only constructive advice would be appreciated...