[1] can be done but takes just a little effort. Once deleted from your mail folder, go to the deleted mail folder and delete the e-mail from there as well. Then send/receive. In me experience that has taken the mail off the server. It is actualy a concession. I personally, and I expect many others do not want mail automatically deleted from the server, as ther is no good way to get a record of that e-mail back to the PC other than forwarding it back to that or another address. The option provided lets you choose which mails you wish to keep on the server and which you wish to get rid off. I know many would like the option of deleting all when downloaded, but we don't have that.
[2] se [1]
[3] Can't say I've noticed that on my devices. Just checked my K-Jam to see if maybe i missed it, because if I'm on the headset, the phone is normally put away. Nope it has the normal soft keys. Might be 6915 specific.