> But how would I get back out to the previous view, to get
> the list of databases again?

/connect then enter

>Are there ways other than the native SQL commands
>(show tables; show columns from tablename) to display
>the schema(s)?

/col_info /table_info etc. ... type /help and press enter for a list

> Can I load data into variables and look at them?

Yes, you can, though I forget whether that's something I had to patch.

>I'm just not sure how to submit shell commands other than 
> SQL statements, executed as soon as the semicolon gets 
> entered.

type a forward slash, the command, then press enter