The easiest way to do it is with **synclient**.
Use:
synclient -l
to list all options and their current settings and then you can use:
synclient var1=value1 [var2=value2] ...
to change the different options.
To make changes permanent you can either create a script and run it on i3 logon or edit the file /etc/X11/xorg.conf.d (if you don't have it copy it from /etc/X11/xorg.conf.d/50-synaptics.conf ). In /etc/X11/xorg.conf.d you should write your settings under:
Section "InputClass"
Identifier "touchpad"
Driver "synaptics"
MatchIsTouchpad "on"
In the form:
Option "var1" "value1"
...
For tap-click and vertical scroll on right you should add:
Option "TapButton1" "1"
Option "VertEdgeScroll" "0"
You can also take a look at arch linux wiki page about Touchpad_Synaptics
If you want more gestures take a look at touchegg