Cathie

Hi, a couple of things - full sun all day, but depending on how hot it gets there, something white, like a tile, could be propped against the pot to keep the roots cooler, though I think your pots are large enough for it not to be a big issue. Don't bother spraying for humidity, it's pretty ineffective, junipers don't need it, and it can cause problems. Concave cutters (8", ~$50/USD) are pretty indispensable for any bonsai work, and Ron's mix should be fine, though some might use even less bark, and more grit, but that may depend on how often you water, the climate there, etc. When you have the cascade out of the pot and into one that allows a horiz. shot of the roots, etc., post it so we can see what the nebari are like and the branching. Both your trees will need some work, but you can wait until you have a better idea (look at books on bonsai to start) of styling and how to get 'there' from being new at it. There's always time to cut, but you can't glue branches back on :-)!