Are these phal hybrids ready for S/H?

[grasshopper]

I should start out with the qualifier that I'm brand new to orchids and have been "winging it" the last few weeks based on the hours spent reading posts from OB. I haven't killed anything yet, and I'm hoping to keep it that way (no promises, though). That said, I've got 2 small phals (both are hybrids) that I have a few questions about.

I received these lil' guys a few weeks ago and they came shipped in 4" plastic pots in a sphag/bark mix medium with a few styrofoam peanuts in the bottom of the pot for air circulation. Their roots look great, and I've noticed some new roots coming in. Everything I've read about repotting to S/H says to wait until there is new root growth so that the new roots grow into the new medium to support the plant (because the older roots will generally rot). My question to those with experience in this area is are these new roots sufficient to repot to S/H? Or should I wait until they are a bit longer?

Also, one of the phals has a yellowing and shriveling leaf (see photos of phal2 yellow leaf)? Am I underwatering it? This phal has more peanuts in the bottom of the pot than it's friend, but it also has sphag/bark lightly around the top. I've been watering once a week, but I'm thinking I may need to bump it up to twice a week.

I keep these little guys in an east windowsill in a room with high/low temps of 78/64 degrees F and average humidity of 55%. I've got a cool mist humidifier running on medium all day, as well as a ceiling fan at medium speed on 24/7. I water the phal1 plant once a week (it has more sphag in the medium) and the phal2 plant once a week, but am thinking of upping it to twice a week (depending on the advice received on this post).

Oh, and my watering routing includes watering with a KLN solution to try and stimulate new root growth. Should I continue to do this?

Thanks!