I got them all working BUT not exacrly the way I want. Here's my .xbindkeysrc
Code:
"xbindkeys_show" 
  control+shift + q

"/usr/bin/xvkbd -xsendevent -text "\[Alt_L]\[Left]""
m:0x0 + b:13
"/usr/bin/xvkbd -xsendevent -text "\[Left]" & sleep .3"
m:0x0 + b:6
"/usr/bin/xvkbd -xsendevent -text "\[Right]""
m:0x0 + b:7
"amixer set Master 2-" 
m:0x0 + b:8
"amixer set Master 1+"      
    m:0x0 + b:9
"/usr/bin/xvkbd -xsendevent -text "\[Control]\[F4]""
m:0x0 + b:2

1. I want my mouse buttons to control Volume Up and Down and they do, but it is not repeatable if I hold the button, meaning if I want to change volume by more than one degree, I need to press the button several times instead of holding it. I want it to work just with holding it pressed just like the volume buttons on my Thinkpad keyboard work.

2. Button 6 and 7 is used to skip 5 seconds of movie playback in smplayer. Here, I want the opposite to the above - I want it NOT to repeat automatically if I hold the key. Right now it does and most often pressing a button results in 30+ seconds skip. As you can see, I tried adding "& sleep" to the bind but it doesn't make any difference.

3, I have a problem with middle mouse button bind. As you can see, it is assigned to close tab (ctrl+f4). The problem is, that it assigned the same action to my trackpoint middle button (which I use for scrolling) and now whenever I scroll with trackpoint, I run into serious risk of closing the tab instead of scrolling it.