How can I delete these by-product addresses ("L_addr1" & "N_addr2") that I do not wish to use?
(or rather just not shown in the interface, in case I accidentally used it when I have 4 or 5 currencies in Coin)
If I were to sent some funds, does the Coin interface allow me to choose which address to send from?
(assume I have multiple addresses in that particular currency)
No way to delete PrivateKeys (it is dangerous anyway, you can lost money owned by that key).
When you are spending money they selected automatically.
We know about a problem in current version. It does not select random new key for accepting change of SendMoney operation. It lowers level of anonimity and will be fixed soon.