All of this kind of thing has been made much easier with a WYSIWYG (what you see is what you get) drag and drop Hud editor in PT4, and viewing marked hands is much easier too.
If you're just getting started with PokerTracker you may want to take a look at PT4 instead.
Since you only just bought PT3 you can upgrade to PT4 for free - simply download and install, and then pre-order in the Community page within PT4. You will need to go through the checkout process but will not be charged.
Get the Public Beta hereTo answer your specific points (in PT3):
To add a stat to the layout you double click it in the list on the left, and to remove a stat double click it on the right.
PT3 doesn't have Hud position options for individual positions (just EP, MP, LP, blinds) so you can't add Raise First In for the button only (although this is available as a custom stat to download for free from
Customize PokerTracker. PT4 has separate positions for SB and BB, and Button and Cutoff, as well as EP and MP options.