Can you send partial amounts of zcash to a zaddress or do you have to send all of it to a zaddress? Reading the tutorial online, they say to use: z_sendmany to send to a z address. But can one send partial amounts to a zaddress from a taddress? Also what if one wanted to send partial amounts from a zaddress to a taddress/zaddress? Is this doable without using z_sendmany option?
z_sendmany can send from either a t or z address to a t or z address, and yes you can send any fraction of the amount from the source t-addr

-@radix42, zcash contributor