Is it possible to change the options of the Terminal without installing the elementary-tweaks tool?! I want to change the transparency to 90%, the theme to "Chalk" and the Cursor shape to I-Beam.
To change the transparency in Terminal you can use gsettings like this:
gsettings set org.pantheon.terminal.settings opacity 90
If you are not happy with the result, you can always change it to a different value or reset it to the default like this:
gsettings reset org.pantheon.terminal.settings opacity
To change the cursor shape, you can execute the following:
gsettings set org.pantheon.terminal.settings cursor-shape I-Beam
Or to find out what other options are supported:
gsettings range org.pantheon.terminal.settings cursor-shape
When you use gsettings to set these options, the changes are applied immediately.
You can change the various colors that are used in Terminal with the palette option, have a look at this setting:
gsettings get org.pantheon.terminal.settings palette
An alternative to using gsettings for changing these settings is the graphical user interface tool dconf-editor.
In elementary OS, dconf-editor is not installed by default however.
So, if you want to use this method, you may have to install the package using either Software Center or by running this in Terminal:
sudo apt-get install dconf-editor
Start dconf-editor and go to:
org > pantheon > terminal > settings
Here you can set the transparency using the opacity option or change the cursor shape by selecting a different value for cursor-shape.
Command to change the Gtk theme (note that I'm using Numix as an example):
gsettings set org.gnome.desktop.interface gtk-theme "Numix"
Command to change the icon theme:
gsettings set org.gnome.desktop.interface icon-theme "Numix"
Command to change the metacity theme:
gsettings set org.gnome.desktop.wm.preferences theme "Numix"
As for the cursor theme, here's a relevant question.
I don't quite understand what kind of transparency are you trying to set.