If I haven't said so already, welcome to the Orchid Board, Piper 23.
I remember your previous thread about receiving these orchids as a gift a year ago, and detailing for us the care they have received since you got them, including that you watered once a week. I did not post in that thread but agree that those orchids all looked dehydrated, some a little worse than others.
You also said, quote, "I re-potted them last month for the first time. I trimmed dead roots but there were active roots."
It has been just a little over three weeks since that post, and you mention that since then, you have slightly increased watering based on the weight of the pot. Trust me when I say three weeks of just a little bit more water is not enough to cause any of those plants to get root rot and die. There was something going on way before now.
I wonder about what type of media they were potted in, and for how long, before your repot a month or so ago. In your photos, they all appear to be in pots with chunky media and plenty of drainage holes, but was that always the case? Can you be absolutely sure that the roots you cut off were dead? If they were in the center of the pot, just having a brownish color does not necessarily mean they are dead.
As to your two new orchids, the crazy long roots are called aerial roots, and they are common on many types of orchids. I don't recommend trying to force them into the pot.
If you haven't come across it already, there is a "sticky" thread in the Beginner's section of the forum, found near the top, above the new posts, called "The Phal Abuse Stops Here." Don't be put off by the title of it.
It contains lots of advice for beginners.
I'm sure others will chime in here. Best of luck to you going forward. I don't think anyone here can claim to have never killed an orchid. We learn as we go, and you'll find what works best for your plants, in your growing conditions.