It's Arial but the auhor of this message usees a comma as an apostrophe.

Arial Black with a touch of WordArt or other vectorial software.

Dans les options de recherche, coche l'option "100% gratuit". Alors ne s'afficheront que les polices que tu pourras utiliser sans limite d'usage non-commercial.
http://www.dafont.com/fr/theme.php?cat=603&fpp=100&a=on&l[]=10&l[]=1
Savoir ce qu'est une police "nice" est une question de goût, difficile donc de t'orienter.
(perso, je ne trouve pas très "nice" les deux exemples que tu montres)

I think it's Stonehenge with the G of an other font.

Some other "stencil" styles : http://www.dafont.com/theme.php?cat=114&fpp=50&af=on

Coup de change, c'est ma police "standard".

What's append exactly ?
Have you read the FAQ ? http://www.dafont.com/faq.php#win

You don't need special equipment to use any TTF font, including non-latin (American) alphabet (I use often asian alphabets) or even symboles (like that http://www.dafont.com/theme.php?cat=701 ).
You are able to use every fonts available on DaFont without special equipment.

To install a font on Windows : http://www.dafont.com/fr/faq.php#win
If you have some difficulties with this process, you can ask questions.

After install, you can use the font with every installed softwares (using fonts of course) and every printers (younger than 30 years).

It's very close Furtura Black but the "I" is a little bit different.

I know this font with the name "Lower Westside" but I don't know a reliable website to download it or buy it.
I got it on a CD many year ago.

A font file is a file same an other. You can store it everywere you want.
If you don't use some fonts, don't install them. Just store it in an other directory an install only the fonts you need.
It will be easier to use.

Justice is a question of point of view.
Remember that the villain is the hero of is ows history.