i used to use the 9300, pretty much identical apart from wlan, so maybe i can help.
the sim memory is available from the contacts menu, just click it to open it. attaching to the calendar is done if the contact has an email address - you cant store that info on the sim so you cant do this
you cannot add applications to the front part at all. only the pda side.
the memory option i mention above, note that the phone will always default to its own memory - its designed that way
you cant selectively delete things from the call registry, it gives you totals etc based on your calls. beleive me when i say to you its better this way, especially when you need to total up you call times at the end of the month.