Growing fast is a good sign, but getting soaked every 5 days is suicidal, so wait til more of the soil is dry between waterings and wait only til the last frost of your area is passed before getting it outside (hopefully in very gritty compost with lots of bark vs whatever peaty soil it might have come in), and hopefully any glued on pebbles have been discarded. Stop spraying - junipers don't need added humidity anyhow (fresh air is lots better) and spraying never adds enough to matter anyhow.

What you see is juvenile growth. Junipers do this (although the juvenile growth looks different on each variety) when they are stressed. Your tree needs far more light than it is getting, and much less dry heat than it is getting.

Good luck with it!

Here is a link that might be useful: Sashi-eda Bonsai