Notepad++ Multi editing

Yes: simply press and hold the Alt key, click and drag to select the lines whose columns you wish to edit, and begin typing.
You can also go to Settings > Preferences…, and in the Editing tab, turn on multi-editing, to enable selection of multiple separate regions or columns of text to edit at once.
It’s much more intuitive, as you can see your edits live as you type.

Ctrl+Backspace inserts a small box instead of erasing

The “box” you’re seeing is what is known as a control character. The box is displayed because, as you’ve discovered, not all programs handle the ctrl+backspace to remove a word.
This control character is one of 33 “non-printing” characters in the 128 character ASCII character-encoding scheme.

Weird Characters

Can somebody please explain tome what these are. The other day, i was trying to close Notepad++ using the Esc button. After seeing that it wouldn’t work, i tried pressing Ctrl+Esc. Then Shift+Esc. This printed typed Esc (in bold) on my notepad. You can also type this into cmd. Depending on the text editor u use, it may show it or not. I use Notepad++. Here is a list of other special commands(if you type them into cmd, most of the print out a character, such as a heart of spade.): 

~ Shift + Esc = (ESC)
~ Ctrl + E = (ENQ)
~ Ctrl + R = (DC2)
~ Ctrl + Pause\Break = (ETX)
 ~ Ctrl + Shift + Y = (EM)
~ Ctrl + Shift + W = (ETB)
~ Ctrl + Shift + O = (SI)
~ Ctrl + Shift + A = (SOH)
~ Ctrl + Shift + D = (EOT)
~ Ctrl + Shift + G = (BEL)
~ Ctrl + Shift + H = (BS)
~ Ctrl + Shift + Z = (SUB)
~ Ctrl + Shift + X = (CAN)
~ Ctrl + Shift + C = (ETX)
~ Ctrl + Shift + v = (SYN)
~ Ctrl + Shift + B = (STX)
~ Ctrl + Shift + N = (SO)
~ Ctrl + Shift + 6 + (RS)
~ Ctrl + Shift + -(Dash) = (US)

I don’t know what these are called; i accidentally found one while messing with my keyboard, then i tried many different button combinations. You may not be able to seem them up here, but the characters look like the ones in parenthesis ieg. (SUB), (BEL (rings the system bell)) 
On some text editors, it they will show up like symbols. Note that these characters cannot be copied and pasted.
Attached is a screen shot.


Attachments:
bandicam 2012-06-12 07-03-51-159.jpg
bandicam 2012-06-12 07-03-51-159.jpg [ 82.99 KiB | Viewed 483 times ]

those are ASCII or Unicode characters that you’ve found the keyboard shortcuts for. for example on my keyboard layout on linux the code u00f5 is used to produce õ which is it’s ID in the unicode character set.