Weird roots with leaves?

Hey all,

First time grower almost a month into veg and things are going pretty well, but would really appreciate any advice from those who are more experienced on a few issues.

First, thin root-like structures have been poking thru the soil and then sprouting leaves of their own. I know roots will poke thru the soil when it's too dry, but I don't think this is the case. What should I give/take away?

Secondly, two of my otherwise healthy looking plants are having their leaves curl upwards and inwards. There seems to be a number of possible reasons for this, but where should I start? Is it possible that too much heat would cause this? There is a little browning on some of the lower leaves, but otherwise color is consistent.

Thanks

Sometimes when roots come out of the soil and harden they turn into stems basically and grow leaf.
The same happens if you bury the stems down the old stems and nodes will grow roots