I found a build I like, the Half-Orc Shock Trooper, but I don't understand how a rogue (is that what is meant by "thief"?) can choose the Shock Trooper PP when you have to be a fighter to choose it.
The secret here is that the rogue multiclassed fighter in this build.
From this feat you then gain access to both the entire fighter specific feat list, but also all fighter paragon paths.
Also to your aside: there is a bit of history here with the essentials classes that should probably be mentioned. Most PHB1 classes have both their main class (fighter, rogue, cleric, Wizard, Warlord) and then a listed subtype (Weapon master, Scoundrel, Templar, Arcanist, Marshall). This was introduced when the essentials line was put out and new subtypes appears (Knight, thief, War Priest, Mage) (warlord is still out in the cold here :(). Thus thief is a type of rogue, has access to all the rogue feats, but is not as PHB1 rogue as that is referred to as a scoundrel.