New to Neo questions (air roots, rock mounts, watering, light)

[websherpa]

I am new to orchids (not new to horticulture) inspired by some Neofinetia falcata that I happened upon at Young's Plants in Delta, BC (and transported 2 Neos and one Sedirea japonica home to Toronto, Ontario). In particular I was inspired by laval rock mounted orchids, though I am now familiar with the moss mound technique as well.

I have been doing copious reading, but wanted to ask a couple specific questions to gather opinions.

I wanted to repot the orchids from their cramped and algae encrusted plastic pots and attempt a coupl rock mounts.

The rock mounts turned out ok, but I have questions:

Why does one traditionally wrap and cover the air roots? I find them to be aesthetically pleasing to be in the air (other than the ones used for support), in a bonsai fashion.

Is it necessary to use cotton thread in order to help wick water up towards the plant and growing media (I have mine mounted on the rocks in spahgnum, with some spahgnum trailing and some added moss, which gives a nice natural look - but I couldn't quickly find good lava rock - so they may need to be remounted).

How much light should I be giving them? I have to supplement a Northwest facing window with artificial.

How much water? Generally how much fertilizer (types and when)? I am mostly watering with Orchid Champion. My understanding was that these tend to like to be wetter, but....

Now both Neos appear to be growing, particularly obvious from the air root growth, tips of which are pink or red. But one Neo's leaves are much lighter or yellower in colour in places (this one is also older with more "chicks" - I appologize for not knowing the terminology yet). Is this a concern? The younger smaller one is greener in colour.

Is there any book or online reference to rock mounted orchid culturing? Particularly for the smaller orchids?

Since repotting the Sedirea (into a sphagnum ball) its lowest leaf has begun to yellow from the crown outward and is obviously going to fall off. Should I be concerned?

I'm wondering exactly how to give these little gems the best kick start (i.e. conditions) I can without a greenhouse to get them happy and healthy. (I was thinking about putting them in a fish tank to raise the humidity / warmth...)

Many thanks for any suggestions!

(And yes, I will post pictures as soon as I can.)