New Orchid Mom Here - Question about Growth

First Orchid: 2 new interesting growths - what are these called ? Second orchid: same thing as first orchid growth. Curious to know what type of growth it is! Third orchid: has a root growing under a leaf. Do I leave it there or try to support it? What type of root is it? I’ve done a little research about keikis. Do any of my orchids have those? If so what is the care for them and if I just let them be? Background: all three of my orchids are by a south facing window. I live in the Midwest so it’s currently winter (don’t worry my room is very warm for them) and I mist them with spring water about once a week. I did cut off some old dried out spikes (they were browning) and it does seem it promoted new growth. I am just curious what the type of growth these plants got! Thank you.